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📁 ..	-	2026-03-21 15:45
📄 __init__.py from . import toimpl from .base import AbstractOperations from .base import BatchOperations from .base import Operations from .ops import MigrateOperation __all__ = [ "AbstractOperations", "Operations", "BatchOperations", "MigrateOperation", ]	262 B	2026-01-20 12:58
📁 __pycache__	-	2026-03-21 15:45
📄 base.py from __future__ import annotations from contextlib import contextmanager import re import textwrap from typing import Any from typing import Awaitable from typing import Callable from typing import Dict from typing import Iterator from typing import List # noqa from typing import Mapping from typing import Optional from typing import Sequence # noqa from typing import Tuple from typing import Type # noqa from typing import TYPE_CHECKING from typing import TypeVar from typing import Union from sqlalchemy.sql.elements import conv from . import batch from . import schemaobj from .. import util from ..util import sqla_compat from ..util.compat import formatannotation_fwdref from ..util.compat import inspect_formatargspec from ..util.compat import inspect_getfullargspec from ..util.sqla_compat import _literal_bindparam if TYPE_CHECKING: from typing import Literal from sqlalchemy import Table from sqlalchemy.engine import Connection from sqlalchemy.sql.expression import BinaryExpression from sqlalchemy.sql.expression import TableClause from sqlalchemy.sql.expression import TextClause from sqlalchemy.sql.expression import Update from sqlalchemy.sql.functions import Function from sqlalchemy.sql.schema import Column from sqlalchemy.sql.schema import Computed from sqlalchemy.sql.schema import Identity from sqlalchemy.sql.schema import SchemaItem from sqlalchemy.types import TypeEngine from .batch import BatchOperationsImpl from .ops import MigrateOperation from ..ddl import DefaultImpl from ..runtime.migration import MigrationContext __all__ = ("Operations", "BatchOperations") _T = TypeVar("_T") class AbstractOperations(util.ModuleClsProxy): """Base class for Operations and BatchOperations. .. versionadded:: 1.11.0 """ impl: Union[DefaultImpl, BatchOperationsImpl] _to_impl = util.Dispatcher() def __init__( self, migration_context: MigrationContext, impl: Optional[BatchOperationsImpl] = None, ) -> None: """Construct a new :class:`.Operations` :param migration_context: a :class:`.MigrationContext` instance. """ self.migration_context = migration_context if impl is None: self.impl = migration_context.impl else: self.impl = impl self.schema_obj = schemaobj.SchemaObjects(migration_context) @classmethod def register_operation( cls, name: str, sourcename: Optional[str] = None ) -> Callable[..., Any]: """Register a new operation for this class. This method is normally used to add new operations to the :class:`.Operations` class, and possibly the :class:`.BatchOperations` class as well. All Alembic migration operations are implemented via this system, however the system is also available as a public API to facilitate adding custom operations. .. seealso:: :ref:`operation_plugins` """ def register(op_cls): if sourcename is None: fn = getattr(op_cls, name) source_name = fn.__name__ else: fn = getattr(op_cls, sourcename) source_name = fn.__name__ spec = inspect_getfullargspec(fn) name_args = spec[0] assert name_args[0:2] == ["cls", "operations"] name_args[0:2] = ["self"] args = inspect_formatargspec( spec, formatannotation=formatannotation_fwdref ) num_defaults = len(spec[3]) if spec[3] else 0 if num_defaults: defaulted_vals = name_args[0 - num_defaults :] else: defaulted_vals = () defaulted_vals += tuple(spec[4]) # here, we are using formatargspec in a different way in order # to get a string that will re-apply incoming arguments to a new # function call apply_kw = inspect_formatargspec( name_args + spec[4], spec[1], spec[2], defaulted_vals, formatvalue=lambda x: "=" + x, formatannotation=formatannotation_fwdref, ) args = re.sub( r'[_]?ForwardRef\(([\'"].+?[\'"])\)', lambda m: m.group(1), args, ) func_text = textwrap.dedent( """\ def %(name)s%(args)s: %(doc)r return op_cls.%(source_name)s%(apply_kw)s """ % { "name": name, "source_name": source_name, "args": args, "apply_kw": apply_kw, "doc": fn.__doc__, } ) globals_ = dict(globals()) globals_.update({"op_cls": op_cls}) lcl = {} exec(func_text, globals_, lcl) setattr(cls, name, lcl[name]) fn.__func__.__doc__ = ( "This method is proxied on " "the :class:`.%s` class, via the :meth:`.%s.%s` method." % (cls.__name__, cls.__name__, name) ) if hasattr(fn, "_legacy_translations"): lcl[name]._legacy_translations = fn._legacy_translations return op_cls return register @classmethod def implementation_for(cls, op_cls: Any) -> Callable[..., Any]: """Register an implementation for a given :class:`.MigrateOperation`. This is part of the operation extensibility API. .. seealso:: :ref:`operation_plugins` - example of use """ def decorate(fn): cls._to_impl.dispatch_for(op_cls)(fn) return fn return decorate @classmethod @contextmanager def context( cls, migration_context: MigrationContext ) -> Iterator[Operations]: op = Operations(migration_context) op._install_proxy() yield op op._remove_proxy() @contextmanager def batch_alter_table( self, table_name: str, schema: Optional[str] = None, recreate: Literal["auto", "always", "never"] = "auto", partial_reordering: Optional[tuple] = None, copy_from: Optional[Table] = None, table_args: Tuple[Any, ...] = (), table_kwargs: Mapping[str, Any] = util.immutabledict(), reflect_args: Tuple[Any, ...] = (), reflect_kwargs: Mapping[str, Any] = util.immutabledict(), naming_convention: Optional[Dict[str, str]] = None, ) -> Iterator[BatchOperations]: """Invoke a series of per-table migrations in batch. Batch mode allows a series of operations specific to a table to be syntactically grouped together, and allows for alternate modes of table migration, in particular the "recreate" style of migration required by SQLite. "recreate" style is as follows: 1. A new table is created with the new specification, based on the migration directives within the batch, using a temporary name. 2. the data copied from the existing table to the new table. 3. the existing table is dropped. 4. the new table is renamed to the existing table name. The directive by default will only use "recreate" style on the SQLite backend, and only if directives are present which require this form, e.g. anything other than ``add_column()``. The batch operation on other backends will proceed using standard ALTER TABLE operations. The method is used as a context manager, which returns an instance of :class:`.BatchOperations`; this object is the same as :class:`.Operations` except that table names and schema names are omitted. E.g.:: with op.batch_alter_table("some_table") as batch_op: batch_op.add_column(Column("foo", Integer)) batch_op.drop_column("bar") The operations within the context manager are invoked at once when the context is ended. When run against SQLite, if the migrations include operations not supported by SQLite's ALTER TABLE, the entire table will be copied to a new one with the new specification, moving all data across as well. The copy operation by default uses reflection to retrieve the current structure of the table, and therefore :meth:`.batch_alter_table` in this mode requires that the migration is run in "online" mode. The ``copy_from`` parameter may be passed which refers to an existing :class:`.Table` object, which will bypass this reflection step. .. note:: The table copy operation will currently not copy CHECK constraints, and may not copy UNIQUE constraints that are unnamed, as is possible on SQLite. See the section :ref:`sqlite_batch_constraints` for workarounds. :param table_name: name of table :param schema: optional schema name. :param recreate: under what circumstances the table should be recreated. At its default of ``"auto"``, the SQLite dialect will recreate the table if any operations other than ``add_column()``, ``create_index()``, or ``drop_index()`` are present. Other options include ``"always"`` and ``"never"``. :param copy_from: optional :class:`~sqlalchemy.schema.Table` object that will act as the structure of the table being copied. If omitted, table reflection is used to retrieve the structure of the table. .. seealso:: :ref:`batch_offline_mode` :paramref:`~.Operations.batch_alter_table.reflect_args` :paramref:`~.Operations.batch_alter_table.reflect_kwargs` :param reflect_args: a sequence of additional positional arguments that will be applied to the table structure being reflected / copied; this may be used to pass column and constraint overrides to the table that will be reflected, in lieu of passing the whole :class:`~sqlalchemy.schema.Table` using :paramref:`~.Operations.batch_alter_table.copy_from`. :param reflect_kwargs: a dictionary of additional keyword arguments that will be applied to the table structure being copied; this may be used to pass additional table and reflection options to the table that will be reflected, in lieu of passing the whole :class:`~sqlalchemy.schema.Table` using :paramref:`~.Operations.batch_alter_table.copy_from`. :param table_args: a sequence of additional positional arguments that will be applied to the new :class:`~sqlalchemy.schema.Table` when created, in addition to those copied from the source table. This may be used to provide additional constraints such as CHECK constraints that may not be reflected. :param table_kwargs: a dictionary of additional keyword arguments that will be applied to the new :class:`~sqlalchemy.schema.Table` when created, in addition to those copied from the source table. This may be used to provide for additional table options that may not be reflected. :param naming_convention: a naming convention dictionary of the form described at :ref:`autogen_naming_conventions` which will be applied to the :class:`~sqlalchemy.schema.MetaData` during the reflection process. This is typically required if one wants to drop SQLite constraints, as these constraints will not have names when reflected on this backend. Requires SQLAlchemy 0.9.4* or greater. .. seealso:: :ref:`dropping_sqlite_foreign_keys` :param partial_reordering: a list of tuples, each suggesting a desired ordering of two or more columns in the newly created table. Requires that :paramref:`.batch_alter_table.recreate` is set to ``"always"``. Examples, given a table with columns "a", "b", "c", and "d": Specify the order of all columns:: with op.batch_alter_table( "some_table", recreate="always", partial_reordering=[("c", "d", "a", "b")], ) as batch_op: pass Ensure "d" appears before "c", and "b", appears before "a":: with op.batch_alter_table( "some_table", recreate="always", partial_reordering=[("d", "c"), ("b", "a")], ) as batch_op: pass The ordering of columns not included in the partial_reordering set is undefined. Therefore it is best to specify the complete ordering of all columns for best results. .. versionadded:: 1.4.0 .. note:: batch mode requires SQLAlchemy 0.8 or above. .. seealso:: :ref:`batch_migrations` """ impl = batch.BatchOperationsImpl( self, table_name, schema, recreate, copy_from, table_args, table_kwargs, reflect_args, reflect_kwargs, naming_convention, partial_reordering, ) batch_op = BatchOperations(self.migration_context, impl=impl) yield batch_op impl.flush() def get_context(self) -> MigrationContext: """Return the :class:`.MigrationContext` object that's currently in use. """ return self.migration_context def invoke(self, operation: MigrateOperation) -> Any: """Given a :class:`.MigrateOperation`, invoke it in terms of this :class:`.Operations` instance. """ fn = self._to_impl.dispatch( operation, self.migration_context.impl.__dialect__ ) return fn(self, operation) def f(self, name: str) -> conv: """Indicate a string name that has already had a naming convention applied to it. This feature combines with the SQLAlchemy ``naming_convention`` feature to disambiguate constraint names that have already had naming conventions applied to them, versus those that have not. This is necessary in the case that the ``"%(constraint_name)s"`` token is used within a naming convention, so that it can be identified that this particular name should remain fixed. If the :meth:`.Operations.f` is used on a constraint, the naming convention will not take effect:: op.add_column("t", "x", Boolean(name=op.f("ck_bool_t_x"))) Above, the CHECK constraint generated will have the name ``ck_bool_t_x`` regardless of whether or not a naming convention is in use. Alternatively, if a naming convention is in use, and 'f' is not used, names will be converted along conventions. If the ``target_metadata`` contains the naming convention ``{"ck": "ck_bool_%(table_name)s_%(constraint_name)s"}``, then the output of the following: op.add_column("t", "x", Boolean(name="x")) will be:: CONSTRAINT ck_bool_t_x CHECK (x in (1, 0))) The function is rendered in the output of autogenerate when a particular constraint name is already converted. """ return conv(name) def inline_literal( self, value: Union[str, int], type_: Optional[TypeEngine[Any]] = None ) -> _literal_bindparam: r"""Produce an 'inline literal' expression, suitable for using in an INSERT, UPDATE, or DELETE statement. When using Alembic in "offline" mode, CRUD operations aren't compatible with SQLAlchemy's default behavior surrounding literal values, which is that they are converted into bound values and passed separately into the ``execute()`` method of the DBAPI cursor. An offline SQL script needs to have these rendered inline. While it should always be noted that inline literal values are an enormous security hole in an application that handles untrusted input, a schema migration is not run in this context, so literals are safe to render inline, with the caveat that advanced types like dates may not be supported directly by SQLAlchemy. See :meth:`.Operations.execute` for an example usage of :meth:`.Operations.inline_literal`. The environment can also be configured to attempt to render "literal" values inline automatically, for those simple types that are supported by the dialect; see :paramref:`.EnvironmentContext.configure.literal_binds` for this more recently added feature. :param value: The value to render. Strings, integers, and simple numerics should be supported. Other types like boolean, dates, etc. may or may not be supported yet by various backends. :param type\_: optional - a :class:`sqlalchemy.types.TypeEngine` subclass stating the type of this value. In SQLAlchemy expressions, this is usually derived automatically from the Python type of the value itself, as well as based on the context in which the value is used. .. seealso:: :paramref:`.EnvironmentContext.configure.literal_binds` """ return sqla_compat._literal_bindparam(None, value, type_=type_) def get_bind(self) -> Connection: """Return the current 'bind'. Under normal circumstances, this is the :class:`~sqlalchemy.engine.Connection` currently being used to emit SQL to the database. In a SQL script context, this value is ``None``. [TODO: verify this] """ return self.migration_context.impl.bind # type: ignore[return-value] def run_async( self, async_function: Callable[..., Awaitable[_T]], args: Any, kw_args: Any, ) -> _T: """Invoke the given asynchronous callable, passing an asynchronous :class:`~sqlalchemy.ext.asyncio.AsyncConnection` as the first argument. This method allows calling async functions from within the synchronous ``upgrade()`` or ``downgrade()`` alembic migration method. The async connection passed to the callable shares the same transaction as the connection running in the migration context. Any additional arg or kw_arg passed to this function are passed to the provided async function. .. versionadded: 1.11 .. note:: This method can be called only when alembic is called using an async dialect. """ if not sqla_compat.sqla_14_18: raise NotImplementedError("SQLAlchemy 1.4.18+ required") sync_conn = self.get_bind() if sync_conn is None: raise NotImplementedError("Cannot call run_async in SQL mode") if not sync_conn.dialect.is_async: raise ValueError("Cannot call run_async with a sync engine") from sqlalchemy.ext.asyncio import AsyncConnection from sqlalchemy.util import await_only async_conn = AsyncConnection._retrieve_proxy_for_target(sync_conn) return await_only(async_function(async_conn, args, *kw_args)) class Operations(AbstractOperations): """Define high level migration operations. Each operation corresponds to some schema migration operation, executed against a particular :class:`.MigrationContext` which in turn represents connectivity to a database, or a file output stream. While :class:`.Operations` is normally configured as part of the :meth:`.EnvironmentContext.run_migrations` method called from an ``env.py`` script, a standalone :class:`.Operations` instance can be made for use cases external to regular Alembic migrations by passing in a :class:`.MigrationContext`:: from alembic.migration import MigrationContext from alembic.operations import Operations conn = myengine.connect() ctx = MigrationContext.configure(conn) op = Operations(ctx) op.alter_column("t", "c", nullable=True) Note that as of 0.8, most of the methods on this class are produced dynamically using the :meth:`.Operations.register_operation` method. """ if TYPE_CHECKING: # START STUB FUNCTIONS: op_cls # ### the following stubs are generated by tools/write_pyi.py ### # ### do not edit ### def add_column( self, table_name: str, column: Column[Any], , schema: Optional[str] = None, ) -> None: """Issue an "add column" instruction using the current migration context. e.g.:: from alembic import op from sqlalchemy import Column, String op.add_column("organization", Column("name", String())) The :meth:`.Operations.add_column` method typically corresponds to the SQL command "ALTER TABLE... ADD COLUMN". Within the scope of this command, the column's name, datatype, nullability, and optional server-generated defaults may be indicated. .. note:: With the exception of NOT NULL constraints or single-column FOREIGN KEY constraints, other kinds of constraints such as PRIMARY KEY, UNIQUE or CHECK constraints cannot be generated using this method; for these constraints, refer to operations such as :meth:`.Operations.create_primary_key` and :meth:`.Operations.create_check_constraint`. In particular, the following :class:`~sqlalchemy.schema.Column` parameters are ignored: * :paramref:`~sqlalchemy.schema.Column.primary_key` - SQL databases typically do not support an ALTER operation that can add individual columns one at a time to an existing primary key constraint, therefore it's less ambiguous to use the :meth:`.Operations.create_primary_key` method, which assumes no existing primary key constraint is present. * :paramref:`~sqlalchemy.schema.Column.unique` - use the :meth:`.Operations.create_unique_constraint` method * :paramref:`~sqlalchemy.schema.Column.index` - use the :meth:`.Operations.create_index` method The provided :class:`~sqlalchemy.schema.Column` object may include a :class:`~sqlalchemy.schema.ForeignKey` constraint directive, referencing a remote table name. For this specific type of constraint, Alembic will automatically emit a second ALTER statement in order to add the single-column FOREIGN KEY constraint separately:: from alembic import op from sqlalchemy import Column, INTEGER, ForeignKey op.add_column( "organization", Column("account_id", INTEGER, ForeignKey("accounts.id")), ) The column argument passed to :meth:`.Operations.add_column` is a :class:`~sqlalchemy.schema.Column` construct, used in the same way it's used in SQLAlchemy. In particular, values or functions to be indicated as producing the column's default value on the database side are specified using the ``server_default`` parameter, and not ``default`` which only specifies Python-side defaults:: from alembic import op from sqlalchemy import Column, TIMESTAMP, func # specify "DEFAULT NOW" along with the column add op.add_column( "account", Column("timestamp", TIMESTAMP, server_default=func.now()), ) :param table_name: String name of the parent table. :param column: a :class:`sqlalchemy.schema.Column` object representing the new column. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ # noqa: E501 ... def alter_column( self, table_name: str, column_name: str, , nullable: Optional[bool] = None, comment: Union[str, Literal[False], None] = False, server_default: Any = False, new_column_name: Optional[str] = None, type_: Union[TypeEngine, Type[TypeEngine], None] = None, existing_type: Union[TypeEngine, Type[TypeEngine], None] = None, existing_server_default: Union[ str, bool, Identity, Computed, None ] = False, existing_nullable: Optional[bool] = None, existing_comment: Optional[str] = None, schema: Optional[str] = None, kw: Any, ) -> None: r"""Issue an "alter column" instruction using the current migration context. Generally, only that aspect of the column which is being changed, i.e. name, type, nullability, default, needs to be specified. Multiple changes can also be specified at once and the backend should "do the right thing", emitting each change either separately or together as the backend allows. MySQL has special requirements here, since MySQL cannot ALTER a column without a full specification. When producing MySQL-compatible migration files, it is recommended that the ``existing_type``, ``existing_server_default``, and ``existing_nullable`` parameters be present, if not being altered. Type changes which are against the SQLAlchemy "schema" types :class:`~sqlalchemy.types.Boolean` and :class:`~sqlalchemy.types.Enum` may also add or drop constraints which accompany those types on backends that don't support them natively. The ``existing_type`` argument is used in this case to identify and remove a previous constraint that was bound to the type object. :param table_name: string name of the target table. :param column_name: string name of the target column, as it exists before the operation begins. :param nullable: Optional; specify ``True`` or ``False`` to alter the column's nullability. :param server_default: Optional; specify a string SQL expression, :func:`~sqlalchemy.sql.expression.text`, or :class:`~sqlalchemy.schema.DefaultClause` to indicate an alteration to the column's default value. Set to ``None`` to have the default removed. :param comment: optional string text of a new comment to add to the column. .. versionadded:: 1.0.6 :param new_column_name: Optional; specify a string name here to indicate the new name within a column rename operation. :param type\_: Optional; a :class:`~sqlalchemy.types.TypeEngine` type object to specify a change to the column's type. For SQLAlchemy types that also indicate a constraint (i.e. :class:`~sqlalchemy.types.Boolean`, :class:`~sqlalchemy.types.Enum`), the constraint is also generated. :param autoincrement: set the ``AUTO_INCREMENT`` flag of the column; currently understood by the MySQL dialect. :param existing_type: Optional; a :class:`~sqlalchemy.types.TypeEngine` type object to specify the previous type. This is required for all MySQL column alter operations that don't otherwise specify a new type, as well as for when nullability is being changed on a SQL Server column. It is also used if the type is a so-called SQLlchemy "schema" type which may define a constraint (i.e. :class:`~sqlalchemy.types.Boolean`, :class:`~sqlalchemy.types.Enum`), so that the constraint can be dropped. :param existing_server_default: Optional; The existing default value of the column. Required on MySQL if an existing default is not being changed; else MySQL removes the default. :param existing_nullable: Optional; the existing nullability of the column. Required on MySQL if the existing nullability is not being changed; else MySQL sets this to NULL. :param existing_autoincrement: Optional; the existing autoincrement of the column. Used for MySQL's system of altering a column that specifies ``AUTO_INCREMENT``. :param existing_comment: string text of the existing comment on the column to be maintained. Required on MySQL if the existing comment on the column is not being changed. .. versionadded:: 1.0.6 :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param postgresql_using: String argument which will indicate a SQL expression to render within the Postgresql-specific USING clause within ALTER COLUMN. This string is taken directly as raw SQL which must explicitly include any necessary quoting or escaping of tokens within the expression. """ # noqa: E501 ... def bulk_insert( self, table: Union[Table, TableClause], rows: List[dict], , multiinsert: bool = True, ) -> None: """Issue a "bulk insert" operation using the current migration context. This provides a means of representing an INSERT of multiple rows which works equally well in the context of executing on a live connection as well as that of generating a SQL script. In the case of a SQL script, the values are rendered inline into the statement. e.g.:: from alembic import op from datetime import date from sqlalchemy.sql import table, column from sqlalchemy import String, Integer, Date # Create an ad-hoc table to use for the insert statement. accounts_table = table( "account", column("id", Integer), column("name", String), column("create_date", Date), ) op.bulk_insert( accounts_table, [ { "id": 1, "name": "John Smith", "create_date": date(2010, 10, 5), }, { "id": 2, "name": "Ed Williams", "create_date": date(2007, 5, 27), }, { "id": 3, "name": "Wendy Jones", "create_date": date(2008, 8, 15), }, ], ) When using --sql mode, some datatypes may not render inline automatically, such as dates and other special types. When this issue is present, :meth:`.Operations.inline_literal` may be used:: op.bulk_insert( accounts_table, [ { "id": 1, "name": "John Smith", "create_date": op.inline_literal("2010-10-05"), }, { "id": 2, "name": "Ed Williams", "create_date": op.inline_literal("2007-05-27"), }, { "id": 3, "name": "Wendy Jones", "create_date": op.inline_literal("2008-08-15"), }, ], multiinsert=False, ) When using :meth:`.Operations.inline_literal` in conjunction with :meth:`.Operations.bulk_insert`, in order for the statement to work in "online" (e.g. non --sql) mode, the :paramref:`~.Operations.bulk_insert.multiinsert` flag should be set to ``False``, which will have the effect of individual INSERT statements being emitted to the database, each with a distinct VALUES clause, so that the "inline" values can still be rendered, rather than attempting to pass the values as bound parameters. :param table: a table object which represents the target of the INSERT. :param rows: a list of dictionaries indicating rows. :param multiinsert: when at its default of True and --sql mode is not enabled, the INSERT statement will be executed using "executemany()" style, where all elements in the list of dictionaries are passed as bound parameters in a single list. Setting this to False results in individual INSERT statements being emitted per parameter set, and is needed in those cases where non-literal values are present in the parameter sets. """ # noqa: E501 ... def create_check_constraint( self, constraint_name: Optional[str], table_name: str, condition: Union[str, BinaryExpression, TextClause], , schema: Optional[str] = None, kw: Any, ) -> None: """Issue a "create check constraint" instruction using the current migration context. e.g.:: from alembic import op from sqlalchemy.sql import column, func op.create_check_constraint( "ck_user_name_len", "user", func.len(column("name")) > 5, ) CHECK constraints are usually against a SQL expression, so ad-hoc table metadata is usually needed. The function will convert the given arguments into a :class:`sqlalchemy.schema.CheckConstraint` bound to an anonymous table in order to emit the CREATE statement. :param name: Name of the check constraint. The name is necessary so that an ALTER statement can be emitted. For setups that use an automated naming scheme such as that described at :ref:`sqla:constraint_naming_conventions`, ``name`` here can be ``None``, as the event listener will apply the name to the constraint object when it is associated with the table. :param table_name: String name of the source table. :param condition: SQL expression that's the condition of the constraint. Can be a string or SQLAlchemy expression language structure. :param deferrable: optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when issuing DDL for this constraint. :param initially: optional string. If set, emit INITIALLY <value> when issuing DDL for this constraint. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ # noqa: E501 ... def create_exclude_constraint( self, constraint_name: str, table_name: str, elements: Any, *kw: Any, ) -> Optional[Table]: """Issue an alter to create an EXCLUDE constraint using the current migration context. .. note:: This method is Postgresql specific, and additionally requires at least SQLAlchemy 1.0. e.g.:: from alembic import op op.create_exclude_constraint( "user_excl", "user", ("period", "&&"), ("group", "="), where=("group != 'some group'"), ) Note that the expressions work the same way as that of the ``ExcludeConstraint`` object itself; if plain strings are passed, quoting rules must be applied manually. :param name: Name of the constraint. :param table_name: String name of the source table. :param elements: exclude conditions. :param where: SQL expression or SQL string with optional WHERE clause. :param deferrable: optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when issuing DDL for this constraint. :param initially: optional string. If set, emit INITIALLY <value> when issuing DDL for this constraint. :param schema: Optional schema name to operate within. """ # noqa: E501 ... def create_foreign_key( self, constraint_name: Optional[str], source_table: str, referent_table: str, local_cols: List[str], remote_cols: List[str], , onupdate: Optional[str] = None, ondelete: Optional[str] = None, deferrable: Optional[bool] = None, initially: Optional[str] = None, match: Optional[str] = None, source_schema: Optional[str] = None, referent_schema: Optional[str] = None, *dialect_kw: Any, ) -> None: """Issue a "create foreign key" instruction using the current migration context. e.g.:: from alembic import op op.create_foreign_key( "fk_user_address", "address", "user", ["user_id"], ["id"], ) This internally generates a :class:`~sqlalchemy.schema.Table` object containing the necessary columns, then generates a new :class:`~sqlalchemy.schema.ForeignKeyConstraint` object which it then associates with the :class:`~sqlalchemy.schema.Table`. Any event listeners associated with this action will be fired off normally. The :class:`~sqlalchemy.schema.AddConstraint` construct is ultimately used to generate the ALTER statement. :param constraint_name: Name of the foreign key constraint. The name is necessary so that an ALTER statement can be emitted. For setups that use an automated naming scheme such as that described at :ref:`sqla:constraint_naming_conventions`, ``name`` here can be ``None``, as the event listener will apply the name to the constraint object when it is associated with the table. :param source_table: String name of the source table. :param referent_table: String name of the destination table. :param local_cols: a list of string column names in the source table. :param remote_cols: a list of string column names in the remote table. :param onupdate: Optional string. If set, emit ON UPDATE <value> when issuing DDL for this constraint. Typical values include CASCADE, DELETE and RESTRICT. :param ondelete: Optional string. If set, emit ON DELETE <value> when issuing DDL for this constraint. Typical values include CASCADE, DELETE and RESTRICT. :param deferrable: optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when issuing DDL for this constraint. :param source_schema: Optional schema name of the source table. :param referent_schema: Optional schema name of the destination table. """ # noqa: E501 ... def create_index( self, index_name: Optional[str], table_name: str, columns: Sequence[Union[str, TextClause, Function[Any]]], , schema: Optional[str] = None, unique: bool = False, kw: Any, ) -> None: r"""Issue a "create index" instruction using the current migration context. e.g.:: from alembic import op op.create_index("ik_test", "t1", ["foo", "bar"]) Functional indexes can be produced by using the :func:`sqlalchemy.sql.expression.text` construct:: from alembic import op from sqlalchemy import text op.create_index("ik_test", "t1", [text("lower(foo)")]) :param index_name: name of the index. :param table_name: name of the owning table. :param columns: a list consisting of string column names and/or :func:`~sqlalchemy.sql.expression.text` constructs. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param unique: If True, create a unique index. :param quote: Force quoting of this column's name on or off, corresponding to ``True`` or ``False``. When left at its default of ``None``, the column identifier will be quoted according to whether the name is case sensitive (identifiers with at least one upper case character are treated as case sensitive), or if it's a reserved word. This flag is only needed to force quoting of a reserved word which is not known by the SQLAlchemy dialect. :param \kw: Additional keyword arguments not mentioned above are dialect specific, and passed in the form ``<dialectname>_<argname>``. See the documentation regarding an individual dialect at :ref:`dialect_toplevel` for detail on documented arguments. """ # noqa: E501 ... def create_primary_key( self, constraint_name: Optional[str], table_name: str, columns: List[str], , schema: Optional[str] = None, ) -> None: """Issue a "create primary key" instruction using the current migration context. e.g.:: from alembic import op op.create_primary_key("pk_my_table", "my_table", ["id", "version"]) This internally generates a :class:`~sqlalchemy.schema.Table` object containing the necessary columns, then generates a new :class:`~sqlalchemy.schema.PrimaryKeyConstraint` object which it then associates with the :class:`~sqlalchemy.schema.Table`. Any event listeners associated with this action will be fired off normally. The :class:`~sqlalchemy.schema.AddConstraint` construct is ultimately used to generate the ALTER statement. :param constraint_name: Name of the primary key constraint. The name is necessary so that an ALTER statement can be emitted. For setups that use an automated naming scheme such as that described at :ref:`sqla:constraint_naming_conventions` ``name`` here can be ``None``, as the event listener will apply the name to the constraint object when it is associated with the table. :param table_name: String name of the target table. :param columns: a list of string column names to be applied to the primary key constraint. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ # noqa: E501 ... def create_table( self, table_name: str, columns: SchemaItem, *kw: Any ) -> Table: r"""Issue a "create table" instruction using the current migration context. This directive receives an argument list similar to that of the traditional :class:`sqlalchemy.schema.Table` construct, but without the metadata:: from sqlalchemy import INTEGER, VARCHAR, NVARCHAR, Column from alembic import op op.create_table( "account", Column("id", INTEGER, primary_key=True), Column("name", VARCHAR(50), nullable=False), Column("description", NVARCHAR(200)), Column("timestamp", TIMESTAMP, server_default=func.now()), ) Note that :meth:`.create_table` accepts :class:`~sqlalchemy.schema.Column` constructs directly from the SQLAlchemy library. In particular, default values to be created on the database side are specified using the ``server_default`` parameter, and not ``default`` which only specifies Python-side defaults:: from alembic import op from sqlalchemy import Column, TIMESTAMP, func # specify "DEFAULT NOW" along with the "timestamp" column op.create_table( "account", Column("id", INTEGER, primary_key=True), Column("timestamp", TIMESTAMP, server_default=func.now()), ) The function also returns a newly created :class:`~sqlalchemy.schema.Table` object, corresponding to the table specification given, which is suitable for immediate SQL operations, in particular :meth:`.Operations.bulk_insert`:: from sqlalchemy import INTEGER, VARCHAR, NVARCHAR, Column from alembic import op account_table = op.create_table( "account", Column("id", INTEGER, primary_key=True), Column("name", VARCHAR(50), nullable=False), Column("description", NVARCHAR(200)), Column("timestamp", TIMESTAMP, server_default=func.now()), ) op.bulk_insert( account_table, [ {"name": "A1", "description": "account 1"}, {"name": "A2", "description": "account 2"}, ], ) :param table_name: Name of the table :param \columns: collection of :class:`~sqlalchemy.schema.Column` objects within the table, as well as optional :class:`~sqlalchemy.schema.Constraint` objects and :class:`~.sqlalchemy.schema.Index` objects. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param \*kw: Other keyword arguments are passed to the underlying :class:`sqlalchemy.schema.Table` object created for the command. :return: the :class:`~sqlalchemy.schema.Table` object corresponding to the parameters given. """ # noqa: E501 ... def create_table_comment( self, table_name: str, comment: Optional[str], , existing_comment: Optional[str] = None, schema: Optional[str] = None, ) -> None: """Emit a COMMENT ON operation to set the comment for a table. .. versionadded:: 1.0.6 :param table_name: string name of the target table. :param comment: string value of the comment being registered against the specified table. :param existing_comment: String value of a comment already registered on the specified table, used within autogenerate so that the operation is reversible, but not required for direct use. .. seealso:: :meth:`.Operations.drop_table_comment` :paramref:`.Operations.alter_column.comment` """ # noqa: E501 ... def create_unique_constraint( self, constraint_name: Optional[str], table_name: str, columns: Sequence[str], , schema: Optional[str] = None, kw: Any, ) -> Any: """Issue a "create unique constraint" instruction using the current migration context. e.g.:: from alembic import op op.create_unique_constraint("uq_user_name", "user", ["name"]) This internally generates a :class:`~sqlalchemy.schema.Table` object containing the necessary columns, then generates a new :class:`~sqlalchemy.schema.UniqueConstraint` object which it then associates with the :class:`~sqlalchemy.schema.Table`. Any event listeners associated with this action will be fired off normally. The :class:`~sqlalchemy.schema.AddConstraint` construct is ultimately used to generate the ALTER statement. :param name: Name of the unique constraint. The name is necessary so that an ALTER statement can be emitted. For setups that use an automated naming scheme such as that described at :ref:`sqla:constraint_naming_conventions`, ``name`` here can be ``None``, as the event listener will apply the name to the constraint object when it is associated with the table. :param table_name: String name of the source table. :param columns: a list of string column names in the source table. :param deferrable: optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when issuing DDL for this constraint. :param initially: optional string. If set, emit INITIALLY <value> when issuing DDL for this constraint. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ # noqa: E501 ... def drop_column( self, table_name: str, column_name: str, , schema: Optional[str] = None, *kw: Any, ) -> None: """Issue a "drop column" instruction using the current migration context. e.g.:: drop_column("organization", "account_id") :param table_name: name of table :param column_name: name of column :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param mssql_drop_check: Optional boolean. When ``True``, on Microsoft SQL Server only, first drop the CHECK constraint on the column using a SQL-script-compatible block that selects into a @variable from sys.check_constraints, then exec's a separate DROP CONSTRAINT for that constraint. :param mssql_drop_default: Optional boolean. When ``True``, on Microsoft SQL Server only, first drop the DEFAULT constraint on the column using a SQL-script-compatible block that selects into a @variable from sys.default_constraints, then exec's a separate DROP CONSTRAINT for that default. :param mssql_drop_foreign_key: Optional boolean. When ``True``, on Microsoft SQL Server only, first drop a single FOREIGN KEY constraint on the column using a SQL-script-compatible block that selects into a @variable from sys.foreign_keys/sys.foreign_key_columns, then exec's a separate DROP CONSTRAINT for that default. Only works if the column has exactly one FK constraint which refers to it, at the moment. """ # noqa: E501 ... def drop_constraint( self, constraint_name: str, table_name: str, type_: Optional[str] = None, , schema: Optional[str] = None, ) -> None: r"""Drop a constraint of the given name, typically via DROP CONSTRAINT. :param constraint_name: name of the constraint. :param table_name: table name. :param type\_: optional, required on MySQL. can be 'foreignkey', 'primary', 'unique', or 'check'. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ # noqa: E501 ... def drop_index( self, index_name: str, table_name: Optional[str] = None, , schema: Optional[str] = None, kw: Any, ) -> None: r"""Issue a "drop index" instruction using the current migration context. e.g.:: drop_index("accounts") :param index_name: name of the index. :param table_name: name of the owning table. Some backends such as Microsoft SQL Server require this. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param \kw: Additional keyword arguments not mentioned above are dialect specific, and passed in the form ``<dialectname>_<argname>``. See the documentation regarding an individual dialect at :ref:`dialect_toplevel` for detail on documented arguments. """ # noqa: E501 ... def drop_table( self, table_name: str, , schema: Optional[str] = None, kw: Any ) -> None: r"""Issue a "drop table" instruction using the current migration context. e.g.:: drop_table("accounts") :param table_name: Name of the table :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param \kw: Other keyword arguments are passed to the underlying :class:`sqlalchemy.schema.Table` object created for the command. """ # noqa: E501 ... def drop_table_comment( self, table_name: str, , existing_comment: Optional[str] = None, schema: Optional[str] = None, ) -> None: """Issue a "drop table comment" operation to remove an existing comment set on a table. .. versionadded:: 1.0.6 :param table_name: string name of the target table. :param existing_comment: An optional string value of a comment already registered on the specified table. .. seealso:: :meth:`.Operations.create_table_comment` :paramref:`.Operations.alter_column.comment` """ # noqa: E501 ... def execute( self, sqltext: Union[str, TextClause, Update], , execution_options: Optional[dict[str, Any]] = None, ) -> None: r"""Execute the given SQL using the current migration context. The given SQL can be a plain string, e.g.:: op.execute("INSERT INTO table (foo) VALUES ('some value')") Or it can be any kind of Core SQL Expression construct, such as below where we use an update construct:: from sqlalchemy.sql import table, column from sqlalchemy import String from alembic import op account = table("account", column("name", String)) op.execute( account.update() .where(account.c.name == op.inline_literal("account 1")) .values({"name": op.inline_literal("account 2")}) ) Above, we made use of the SQLAlchemy :func:`sqlalchemy.sql.expression.table` and :func:`sqlalchemy.sql.expression.column` constructs to make a brief, ad-hoc table construct just for our UPDATE statement. A full :class:`~sqlalchemy.schema.Table` construct of course works perfectly fine as well, though note it's a recommended practice to at least ensure the definition of a table is self-contained within the migration script, rather than imported from a module that may break compatibility with older migrations. In a SQL script context, the statement is emitted directly to the output stream. There is no return result, however, as this function is oriented towards generating a change script that can run in "offline" mode. Additionally, parameterized statements are discouraged here, as they will not work in offline mode. Above, we use :meth:`.inline_literal` where parameters are to be used. For full interaction with a connected database where parameters can also be used normally, use the "bind" available from the context:: from alembic import op connection = op.get_bind() connection.execute( account.update() .where(account.c.name == "account 1") .values({"name": "account 2"}) ) Additionally, when passing the statement as a plain string, it is first coerceed into a :func:`sqlalchemy.sql.expression.text` construct before being passed along. In the less likely case that the literal SQL string contains a colon, it must be escaped with a backslash, as:: op.execute(r"INSERT INTO table (foo) VALUES ('\:colon_value')") :param sqltext: Any legal SQLAlchemy expression, including: * a string * a :func:`sqlalchemy.sql.expression.text` construct. * a :func:`sqlalchemy.sql.expression.insert` construct. * a :func:`sqlalchemy.sql.expression.update`, :func:`sqlalchemy.sql.expression.insert`, or :func:`sqlalchemy.sql.expression.delete` construct. * Any "executable" described in SQLAlchemy Core documentation, noting that no result set is returned. .. note:: when passing a plain string, the statement is coerced into a :func:`sqlalchemy.sql.expression.text` construct. This construct considers symbols with colons, e.g. ``:foo`` to be bound parameters. To avoid this, ensure that colon symbols are escaped, e.g. ``\:foo``. :param execution_options: Optional dictionary of execution options, will be passed to :meth:`sqlalchemy.engine.Connection.execution_options`. """ # noqa: E501 ... def rename_table( self, old_table_name: str, new_table_name: str, , schema: Optional[str] = None, ) -> None: """Emit an ALTER TABLE to rename a table. :param old_table_name: old name. :param new_table_name: new name. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ # noqa: E501 ... # END STUB FUNCTIONS: op_cls class BatchOperations(AbstractOperations): """Modifies the interface :class:`.Operations` for batch mode. This basically omits the ``table_name`` and ``schema`` parameters from associated methods, as these are a given when running under batch mode. .. seealso:: :meth:`.Operations.batch_alter_table` Note that as of 0.8, most of the methods on this class are produced dynamically using the :meth:`.Operations.register_operation` method. """ impl: BatchOperationsImpl def _noop(self, operation): raise NotImplementedError( "The %s method does not apply to a batch table alter operation." % operation ) if TYPE_CHECKING: # START STUB FUNCTIONS: batch_op # ### the following stubs are generated by tools/write_pyi.py ### # ### do not edit ### def add_column( self, column: Column[Any], , insert_before: Optional[str] = None, insert_after: Optional[str] = None, ) -> None: """Issue an "add column" instruction using the current batch migration context. .. seealso:: :meth:`.Operations.add_column` """ # noqa: E501 ... def alter_column( self, column_name: str, , nullable: Optional[bool] = None, comment: Union[str, Literal[False], None] = False, server_default: Any = False, new_column_name: Optional[str] = None, type_: Union[TypeEngine, Type[TypeEngine], None] = None, existing_type: Union[TypeEngine, Type[TypeEngine], None] = None, existing_server_default: Union[ str, bool, Identity, Computed, None ] = False, existing_nullable: Optional[bool] = None, existing_comment: Optional[str] = None, insert_before: Optional[str] = None, insert_after: Optional[str] = None, kw: Any, ) -> None: """Issue an "alter column" instruction using the current batch migration context. Parameters are the same as that of :meth:`.Operations.alter_column`, as well as the following option(s): :param insert_before: String name of an existing column which this column should be placed before, when creating the new table. .. versionadded:: 1.4.0 :param insert_after: String name of an existing column which this column should be placed after, when creating the new table. If both :paramref:`.BatchOperations.alter_column.insert_before` and :paramref:`.BatchOperations.alter_column.insert_after` are omitted, the column is inserted after the last existing column in the table. .. versionadded:: 1.4.0 .. seealso:: :meth:`.Operations.alter_column` """ # noqa: E501 ... def create_check_constraint( self, constraint_name: str, condition: Union[str, BinaryExpression, TextClause], kw: Any, ) -> None: """Issue a "create check constraint" instruction using the current batch migration context. The batch form of this call omits the ``source`` and ``schema`` arguments from the call. .. seealso:: :meth:`.Operations.create_check_constraint` """ # noqa: E501 ... def create_exclude_constraint( self, constraint_name: str, elements: Any, *kw: Any ): """Issue a "create exclude constraint" instruction using the current batch migration context. .. note:: This method is Postgresql specific, and additionally requires at least SQLAlchemy 1.0. .. seealso:: :meth:`.Operations.create_exclude_constraint` """ # noqa: E501 ... def create_foreign_key( self, constraint_name: str, referent_table: str, local_cols: List[str], remote_cols: List[str], , referent_schema: Optional[str] = None, onupdate: Optional[str] = None, ondelete: Optional[str] = None, deferrable: Optional[bool] = None, initially: Optional[str] = None, match: Optional[str] = None, dialect_kw: Any, ) -> None: """Issue a "create foreign key" instruction using the current batch migration context. The batch form of this call omits the ``source`` and ``source_schema`` arguments from the call. e.g.:: with batch_alter_table("address") as batch_op: batch_op.create_foreign_key( "fk_user_address", "user", ["user_id"], ["id"], ) .. seealso:: :meth:`.Operations.create_foreign_key` """ # noqa: E501 ... def create_index( self, index_name: str, columns: List[str], kw: Any ) -> None: """Issue a "create index" instruction using the current batch migration context. .. seealso:: :meth:`.Operations.create_index` """ # noqa: E501 ... def create_primary_key( self, constraint_name: str, columns: List[str] ) -> None: """Issue a "create primary key" instruction using the current batch migration context. The batch form of this call omits the ``table_name`` and ``schema`` arguments from the call. .. seealso:: :meth:`.Operations.create_primary_key` """ # noqa: E501 ... def create_table_comment( self, comment: Optional[str], , existing_comment: Optional[str] = None, ) -> None: """Emit a COMMENT ON operation to set the comment for a table using the current batch migration context. .. versionadded:: 1.6.0 :param comment: string value of the comment being registered against the specified table. :param existing_comment: String value of a comment already registered on the specified table, used within autogenerate so that the operation is reversible, but not required for direct use. """ # noqa: E501 ... def create_unique_constraint( self, constraint_name: str, columns: Sequence[str], kw: Any ) -> Any: """Issue a "create unique constraint" instruction using the current batch migration context. The batch form of this call omits the ``source`` and ``schema`` arguments from the call. .. seealso:: :meth:`.Operations.create_unique_constraint` """ # noqa: E501 ... def drop_column(self, column_name: str, kw: Any) -> None: """Issue a "drop column" instruction using the current batch migration context. .. seealso:: :meth:`.Operations.drop_column` """ # noqa: E501 ... def drop_constraint( self, constraint_name: str, type_: Optional[str] = None ) -> None: """Issue a "drop constraint" instruction using the current batch migration context. The batch form of this call omits the ``table_name`` and ``schema`` arguments from the call. .. seealso:: :meth:`.Operations.drop_constraint` """ # noqa: E501 ... def drop_index(self, index_name: str, kw: Any) -> None: """Issue a "drop index" instruction using the current batch migration context. .. seealso:: :meth:`.Operations.drop_index` """ # noqa: E501 ... def drop_table_comment( self, , existing_comment: Optional[str] = None ) -> None: """Issue a "drop table comment" operation to remove an existing comment set on a table using the current batch operations context. .. versionadded:: 1.6.0 :param existing_comment: An optional string value of a comment already registered on the specified table. """ # noqa: E501 ... def execute( self, sqltext: Union[str, TextClause, Update], *, execution_options: Optional[dict[str, Any]] = None, ) -> None: """Execute the given SQL using the current migration context. .. seealso:: :meth:`.Operations.execute` """ # noqa: E501 ... # END STUB FUNCTIONS: batch_op	70.84 KB	2026-01-20 12:58
📄 batch.py from __future__ import annotations from typing import Any from typing import Dict from typing import List from typing import Optional from typing import Tuple from typing import TYPE_CHECKING from typing import Union from sqlalchemy import CheckConstraint from sqlalchemy import Column from sqlalchemy import ForeignKeyConstraint from sqlalchemy import Index from sqlalchemy import MetaData from sqlalchemy import PrimaryKeyConstraint from sqlalchemy import schema as sql_schema from sqlalchemy import Table from sqlalchemy import types as sqltypes from sqlalchemy.events import SchemaEventTarget from sqlalchemy.util import OrderedDict from sqlalchemy.util import topological from ..util import exc from ..util.sqla_compat import _columns_for_constraint from ..util.sqla_compat import _copy from ..util.sqla_compat import _copy_expression from ..util.sqla_compat import _ensure_scope_for_ddl from ..util.sqla_compat import _fk_is_self_referential from ..util.sqla_compat import _idx_table_bound_expressions from ..util.sqla_compat import _insert_inline from ..util.sqla_compat import _is_type_bound from ..util.sqla_compat import _remove_column_from_collection from ..util.sqla_compat import _resolve_for_variant from ..util.sqla_compat import _select from ..util.sqla_compat import constraint_name_defined from ..util.sqla_compat import constraint_name_string if TYPE_CHECKING: from typing import Literal from sqlalchemy.engine import Dialect from sqlalchemy.sql.elements import ColumnClause from sqlalchemy.sql.elements import quoted_name from sqlalchemy.sql.functions import Function from sqlalchemy.sql.schema import Constraint from sqlalchemy.sql.type_api import TypeEngine from ..ddl.impl import DefaultImpl class BatchOperationsImpl: def __init__( self, operations, table_name, schema, recreate, copy_from, table_args, table_kwargs, reflect_args, reflect_kwargs, naming_convention, partial_reordering, ): self.operations = operations self.table_name = table_name self.schema = schema if recreate not in ("auto", "always", "never"): raise ValueError( "recreate may be one of 'auto', 'always', or 'never'." ) self.recreate = recreate self.copy_from = copy_from self.table_args = table_args self.table_kwargs = dict(table_kwargs) self.reflect_args = reflect_args self.reflect_kwargs = dict(reflect_kwargs) self.reflect_kwargs.setdefault( "listeners", list(self.reflect_kwargs.get("listeners", ())) ) self.reflect_kwargs["listeners"].append( ("column_reflect", operations.impl.autogen_column_reflect) ) self.naming_convention = naming_convention self.partial_reordering = partial_reordering self.batch = [] @property def dialect(self) -> Dialect: return self.operations.impl.dialect @property def impl(self) -> DefaultImpl: return self.operations.impl def _should_recreate(self) -> bool: if self.recreate == "auto": return self.operations.impl.requires_recreate_in_batch(self) elif self.recreate == "always": return True else: return False def flush(self) -> None: should_recreate = self._should_recreate() with _ensure_scope_for_ddl(self.impl.connection): if not should_recreate: for opname, arg, kw in self.batch: fn = getattr(self.operations.impl, opname) fn(arg, kw) else: if self.naming_convention: m1 = MetaData(naming_convention=self.naming_convention) else: m1 = MetaData() if self.copy_from is not None: existing_table = self.copy_from reflected = False else: if self.operations.migration_context.as_sql: raise exc.CommandError( f"This operation cannot proceed in --sql mode; " f"batch mode with dialect " f"{self.operations.migration_context.dialect.name} " # noqa: E501 f"requires a live database connection with which " f'to reflect the table "{self.table_name}". ' f"To generate a batch SQL migration script using " "table " '"move and copy", a complete Table object ' f'should be passed to the "copy_from" argument ' "of the batch_alter_table() method so that table " "reflection can be skipped." ) existing_table = Table( self.table_name, m1, schema=self.schema, autoload_with=self.operations.get_bind(), self.reflect_args, *self.reflect_kwargs, ) reflected = True batch_impl = ApplyBatchImpl( self.impl, existing_table, self.table_args, self.table_kwargs, reflected, partial_reordering=self.partial_reordering, ) for opname, arg, kw in self.batch: fn = getattr(batch_impl, opname) fn(arg, *kw) batch_impl._create(self.impl) def alter_column(self, arg, *kw) -> None: self.batch.append(("alter_column", arg, kw)) def add_column(self, arg, *kw) -> None: if ( "insert_before" in kw or "insert_after" in kw ) and not self._should_recreate(): raise exc.CommandError( "Can't specify insert_before or insert_after when using " "ALTER; please specify recreate='always'" ) self.batch.append(("add_column", arg, kw)) def drop_column(self, arg, *kw) -> None: self.batch.append(("drop_column", arg, kw)) def add_constraint(self, const: Constraint) -> None: self.batch.append(("add_constraint", (const,), {})) def drop_constraint(self, const: Constraint) -> None: self.batch.append(("drop_constraint", (const,), {})) def rename_table(self, arg, *kw): self.batch.append(("rename_table", arg, kw)) def create_index(self, idx: Index) -> None: self.batch.append(("create_index", (idx,), {})) def drop_index(self, idx: Index) -> None: self.batch.append(("drop_index", (idx,), {})) def create_table_comment(self, table): self.batch.append(("create_table_comment", (table,), {})) def drop_table_comment(self, table): self.batch.append(("drop_table_comment", (table,), {})) def create_table(self, table): raise NotImplementedError("Can't create table in batch mode") def drop_table(self, table): raise NotImplementedError("Can't drop table in batch mode") def create_column_comment(self, column): self.batch.append(("create_column_comment", (column,), {})) class ApplyBatchImpl: def __init__( self, impl: DefaultImpl, table: Table, table_args: tuple, table_kwargs: Dict[str, Any], reflected: bool, partial_reordering: tuple = (), ) -> None: self.impl = impl self.table = table # this is a Table object self.table_args = table_args self.table_kwargs = table_kwargs self.temp_table_name = self._calc_temp_name(table.name) self.new_table: Optional[Table] = None self.partial_reordering = partial_reordering # tuple of tuples self.add_col_ordering: Tuple[ Tuple[str, str], ... ] = () # tuple of tuples self.column_transfers = OrderedDict( (c.name, {"expr": c}) for c in self.table.c ) self.existing_ordering = list(self.column_transfers) self.reflected = reflected self._grab_table_elements() @classmethod def _calc_temp_name(cls, tablename: Union[quoted_name, str]) -> str: return ("_alembic_tmp_%s" % tablename)[0:50] def _grab_table_elements(self) -> None: schema = self.table.schema self.columns: Dict[str, Column[Any]] = OrderedDict() for c in self.table.c: c_copy = _copy(c, schema=schema) c_copy.unique = c_copy.index = False # ensure that the type object was copied, # as we may need to modify it in-place if isinstance(c.type, SchemaEventTarget): assert c_copy.type is not c.type self.columns[c.name] = c_copy self.named_constraints: Dict[str, Constraint] = {} self.unnamed_constraints = [] self.col_named_constraints = {} self.indexes: Dict[str, Index] = {} self.new_indexes: Dict[str, Index] = {} for const in self.table.constraints: if _is_type_bound(const): continue elif ( self.reflected and isinstance(const, CheckConstraint) and not const.name ): # TODO: we are skipping unnamed reflected CheckConstraint # because # we have no way to determine _is_type_bound() for these. pass elif constraint_name_string(const.name): self.named_constraints[const.name] = const else: self.unnamed_constraints.append(const) if not self.reflected: for col in self.table.c: for const in col.constraints: if const.name: self.col_named_constraints[const.name] = (col, const) for idx in self.table.indexes: self.indexes[idx.name] = idx # type: ignore[index] for k in self.table.kwargs: self.table_kwargs.setdefault(k, self.table.kwargs[k]) def _adjust_self_columns_for_partial_reordering(self) -> None: pairs = set() col_by_idx = list(self.columns) if self.partial_reordering: for tuple_ in self.partial_reordering: for index, elem in enumerate(tuple_): if index > 0: pairs.add((tuple_[index - 1], elem)) else: for index, elem in enumerate(self.existing_ordering): if index > 0: pairs.add((col_by_idx[index - 1], elem)) pairs.update(self.add_col_ordering) # this can happen if some columns were dropped and not removed # from existing_ordering. this should be prevented already, but # conservatively making sure this didn't happen pairs_list = [p for p in pairs if p[0] != p[1]] sorted_ = list( topological.sort(pairs_list, col_by_idx, deterministic_order=True) ) self.columns = OrderedDict((k, self.columns[k]) for k in sorted_) self.column_transfers = OrderedDict( (k, self.column_transfers[k]) for k in sorted_ ) def _transfer_elements_to_new_table(self) -> None: assert self.new_table is None, "Can only create new table once" m = MetaData() schema = self.table.schema if self.partial_reordering or self.add_col_ordering: self._adjust_self_columns_for_partial_reordering() self.new_table = new_table = Table( self.temp_table_name, m, (list(self.columns.values()) + list(self.table_args)), schema=schema, *self.table_kwargs, ) for const in ( list(self.named_constraints.values()) + self.unnamed_constraints ): const_columns = {c.key for c in _columns_for_constraint(const)} if not const_columns.issubset(self.column_transfers): continue const_copy: Constraint if isinstance(const, ForeignKeyConstraint): if _fk_is_self_referential(const): # for self-referential constraint, refer to the # original* table name, and not _alembic_batch_temp. # This is consistent with how we're handling # FK constraints from other tables; we assume SQLite # no foreign keys just keeps the names unchanged, so # when we rename back, they match again. const_copy = _copy( const, schema=schema, target_table=self.table ) else: # "target_table" for ForeignKeyConstraint.copy() is # only used if the FK is detected as being # self-referential, which we are handling above. const_copy = _copy(const, schema=schema) else: const_copy = _copy( const, schema=schema, target_table=new_table ) if isinstance(const, ForeignKeyConstraint): self._setup_referent(m, const) new_table.append_constraint(const_copy) def _gather_indexes_from_both_tables(self) -> List[Index]: assert self.new_table is not None idx: List[Index] = [] for idx_existing in self.indexes.values(): # this is a lift-and-move from Table.to_metadata if idx_existing._column_flag: # type: ignore continue idx_copy = Index( idx_existing.name, unique=idx_existing.unique, [ _copy_expression(expr, self.new_table) for expr in _idx_table_bound_expressions(idx_existing) ], _table=self.new_table, idx_existing.kwargs, ) idx.append(idx_copy) for index in self.new_indexes.values(): idx.append( Index( index.name, unique=index.unique, [self.new_table.c[col] for col in index.columns.keys()], *index.kwargs, ) ) return idx def _setup_referent( self, metadata: MetaData, constraint: ForeignKeyConstraint ) -> None: spec = constraint.elements[ 0 ]._get_colspec() # type:ignore[attr-defined] parts = spec.split(".") tname = parts[-2] if len(parts) == 3: referent_schema = parts[0] else: referent_schema = None if tname != self.temp_table_name: key = sql_schema._get_table_key(tname, referent_schema) def colspec(elem: Any): return elem._get_colspec() if key in metadata.tables: t = metadata.tables[key] for elem in constraint.elements: colname = colspec(elem).split(".")[-1] if colname not in t.c: t.append_column(Column(colname, sqltypes.NULLTYPE)) else: Table( tname, metadata, [ Column(n, sqltypes.NULLTYPE) for n in [ colspec(elem).split(".")[-1] for elem in constraint.elements ] ], schema=referent_schema, ) def _create(self, op_impl: DefaultImpl) -> None: self._transfer_elements_to_new_table() op_impl.prep_table_for_batch(self, self.table) assert self.new_table is not None op_impl.create_table(self.new_table) try: op_impl._exec( _insert_inline(self.new_table).from_select( list( k for k, transfer in self.column_transfers.items() if "expr" in transfer ), _select( [ transfer["expr"] for transfer in self.column_transfers.values() if "expr" in transfer ] ), ) ) op_impl.drop_table(self.table) except: op_impl.drop_table(self.new_table) raise else: op_impl.rename_table( self.temp_table_name, self.table.name, schema=self.table.schema ) self.new_table.name = self.table.name try: for idx in self._gather_indexes_from_both_tables(): op_impl.create_index(idx) finally: self.new_table.name = self.temp_table_name def alter_column( self, table_name: str, column_name: str, nullable: Optional[bool] = None, server_default: Optional[Union[Function[Any], str, bool]] = False, name: Optional[str] = None, type_: Optional[TypeEngine] = None, autoincrement: Optional[Union[bool, Literal["auto"]]] = None, comment: Union[str, Literal[False]] = False, kw, ) -> None: existing = self.columns[column_name] existing_transfer: Dict[str, Any] = self.column_transfers[column_name] if name is not None and name != column_name: # note that we don't change '.key' - we keep referring # to the renamed column by its old key in _create(). neat! existing.name = name existing_transfer["name"] = name existing_type = kw.get("existing_type", None) if existing_type: resolved_existing_type = _resolve_for_variant( kw["existing_type"], self.impl.dialect ) # pop named constraints for Boolean/Enum for rename if ( isinstance(resolved_existing_type, SchemaEventTarget) and resolved_existing_type.name # type:ignore[attr-defined] # noqa E501 ): self.named_constraints.pop( resolved_existing_type.name, # type:ignore[attr-defined] # noqa E501 None, ) if type_ is not None: type_ = sqltypes.to_instance(type_) # old type is being discarded so turn off eventing # rules. Alternatively we can # erase the events set up by this type, but this is simpler. # we also ignore the drop_constraint that will come here from # Operations.implementation_for(alter_column) if isinstance(existing.type, SchemaEventTarget): existing.type._create_events = ( # type:ignore[attr-defined] existing.type.create_constraint # type:ignore[attr-defined] # noqa ) = False self.impl.cast_for_batch_migrate( existing, existing_transfer, type_ ) existing.type = type_ # we dont* however set events for the new type, because # alter_column is invoked from # Operations.implementation_for(alter_column) which already # will emit an add_constraint() if nullable is not None: existing.nullable = nullable if server_default is not False: if server_default is None: existing.server_default = None else: sql_schema.DefaultClause( server_default # type: ignore[arg-type] )._set_parent( # type:ignore[attr-defined] existing ) if autoincrement is not None: existing.autoincrement = bool(autoincrement) if comment is not False: existing.comment = comment def _setup_dependencies_for_add_column( self, colname: str, insert_before: Optional[str], insert_after: Optional[str], ) -> None: index_cols = self.existing_ordering col_indexes = {name: i for i, name in enumerate(index_cols)} if not self.partial_reordering: if insert_after: if not insert_before: if insert_after in col_indexes: # insert after an existing column idx = col_indexes[insert_after] + 1 if idx < len(index_cols): insert_before = index_cols[idx] else: # insert after a column that is also new insert_before = dict(self.add_col_ordering)[ insert_after ] if insert_before: if not insert_after: if insert_before in col_indexes: # insert before an existing column idx = col_indexes[insert_before] - 1 if idx >= 0: insert_after = index_cols[idx] else: # insert before a column that is also new insert_after = { b: a for a, b in self.add_col_ordering }[insert_before] if insert_before: self.add_col_ordering += ((colname, insert_before),) if insert_after: self.add_col_ordering += ((insert_after, colname),) if ( not self.partial_reordering and not insert_before and not insert_after and col_indexes ): self.add_col_ordering += ((index_cols[-1], colname),) def add_column( self, table_name: str, column: Column[Any], insert_before: Optional[str] = None, insert_after: Optional[str] = None, kw, ) -> None: self._setup_dependencies_for_add_column( column.name, insert_before, insert_after ) # we copy the column because operations.add_column() # gives us a Column that is part of a Table already. self.columns[column.name] = _copy(column, schema=self.table.schema) self.column_transfers[column.name] = {} def drop_column( self, table_name: str, column: Union[ColumnClause[Any], Column[Any]], kw, ) -> None: if column.name in self.table.primary_key.columns: _remove_column_from_collection( self.table.primary_key.columns, column ) del self.columns[column.name] del self.column_transfers[column.name] self.existing_ordering.remove(column.name) # pop named constraints for Boolean/Enum for rename if ( "existing_type" in kw and isinstance(kw["existing_type"], SchemaEventTarget) and kw["existing_type"].name # type:ignore[attr-defined] ): self.named_constraints.pop( kw["existing_type"].name, None # type:ignore[attr-defined] ) def create_column_comment(self, column): """the batch table creation function will issue create_column_comment on the real "impl" as part of the create table process. That is, the Column object will have the comment on it already, so when it is received by add_column() it will be a normal part of the CREATE TABLE and doesn't need an extra step here. """ def create_table_comment(self, table): """the batch table creation function will issue create_table_comment on the real "impl" as part of the create table process. """ def drop_table_comment(self, table): """the batch table creation function will issue drop_table_comment on the real "impl" as part of the create table process. """ def add_constraint(self, const: Constraint) -> None: if not constraint_name_defined(const.name): raise ValueError("Constraint must have a name") if isinstance(const, sql_schema.PrimaryKeyConstraint): if self.table.primary_key in self.unnamed_constraints: self.unnamed_constraints.remove(self.table.primary_key) if constraint_name_string(const.name): self.named_constraints[const.name] = const else: self.unnamed_constraints.append(const) def drop_constraint(self, const: Constraint) -> None: if not const.name: raise ValueError("Constraint must have a name") try: if const.name in self.col_named_constraints: col, const = self.col_named_constraints.pop(const.name) for col_const in list(self.columns[col.name].constraints): if col_const.name == const.name: self.columns[col.name].constraints.remove(col_const) elif constraint_name_string(const.name): const = self.named_constraints.pop(const.name) elif const in self.unnamed_constraints: self.unnamed_constraints.remove(const) except KeyError: if _is_type_bound(const): # type-bound constraints are only included in the new # table via their type object in any case, so ignore the # drop_constraint() that comes here via the # Operations.implementation_for(alter_column) return raise ValueError("No such constraint: '%s'" % const.name) else: if isinstance(const, PrimaryKeyConstraint): for col in const.columns: self.columns[col.name].primary_key = False def create_index(self, idx: Index) -> None: self.new_indexes[idx.name] = idx # type: ignore[index] def drop_index(self, idx: Index) -> None: try: del self.indexes[idx.name] # type: ignore[arg-type] except KeyError: raise ValueError("No such index: '%s'" % idx.name) def rename_table(self, arg, *kw): raise NotImplementedError("TODO")	26.3 KB	2026-01-20 12:58
📄 ops.py from __future__ import annotations from abc import abstractmethod import re from typing import Any from typing import Callable from typing import cast from typing import FrozenSet from typing import Iterator from typing import List from typing import MutableMapping from typing import Optional from typing import Sequence from typing import Set from typing import Tuple from typing import Type from typing import TYPE_CHECKING from typing import Union from sqlalchemy.types import NULLTYPE from . import schemaobj from .base import BatchOperations from .base import Operations from .. import util from ..util import sqla_compat if TYPE_CHECKING: from typing import Literal from sqlalchemy.sql.dml import Insert from sqlalchemy.sql.dml import Update from sqlalchemy.sql.elements import BinaryExpression from sqlalchemy.sql.elements import ColumnElement from sqlalchemy.sql.elements import conv from sqlalchemy.sql.elements import quoted_name from sqlalchemy.sql.elements import TextClause from sqlalchemy.sql.functions import Function from sqlalchemy.sql.schema import CheckConstraint from sqlalchemy.sql.schema import Column from sqlalchemy.sql.schema import Computed from sqlalchemy.sql.schema import Constraint from sqlalchemy.sql.schema import ForeignKeyConstraint from sqlalchemy.sql.schema import Identity from sqlalchemy.sql.schema import Index from sqlalchemy.sql.schema import MetaData from sqlalchemy.sql.schema import PrimaryKeyConstraint from sqlalchemy.sql.schema import SchemaItem from sqlalchemy.sql.schema import Table from sqlalchemy.sql.schema import UniqueConstraint from sqlalchemy.sql.selectable import TableClause from sqlalchemy.sql.type_api import TypeEngine from ..autogenerate.rewriter import Rewriter from ..runtime.migration import MigrationContext class MigrateOperation: """base class for migration command and organization objects. This system is part of the operation extensibility API. .. seealso:: :ref:`operation_objects` :ref:`operation_plugins` :ref:`customizing_revision` """ @util.memoized_property def info(self): """A dictionary that may be used to store arbitrary information along with this :class:`.MigrateOperation` object. """ return {} _mutations: FrozenSet[Rewriter] = frozenset() def reverse(self) -> MigrateOperation: raise NotImplementedError def to_diff_tuple(self) -> Tuple[Any, ...]: raise NotImplementedError class AddConstraintOp(MigrateOperation): """Represent an add constraint operation.""" add_constraint_ops = util.Dispatcher() @property def constraint_type(self): raise NotImplementedError() @classmethod def register_add_constraint(cls, type_: str) -> Callable: def go(klass): cls.add_constraint_ops.dispatch_for(type_)(klass.from_constraint) return klass return go @classmethod def from_constraint(cls, constraint: Constraint) -> AddConstraintOp: return cls.add_constraint_ops.dispatch(constraint.__visit_name__)( constraint ) @abstractmethod def to_constraint( self, migration_context: Optional[MigrationContext] = None ) -> Constraint: pass def reverse(self) -> DropConstraintOp: return DropConstraintOp.from_constraint(self.to_constraint()) def to_diff_tuple(self) -> Tuple[str, Constraint]: return ("add_constraint", self.to_constraint()) @Operations.register_operation("drop_constraint") @BatchOperations.register_operation("drop_constraint", "batch_drop_constraint") class DropConstraintOp(MigrateOperation): """Represent a drop constraint operation.""" def __init__( self, constraint_name: Optional[sqla_compat._ConstraintNameDefined], table_name: str, type_: Optional[str] = None, , schema: Optional[str] = None, _reverse: Optional[AddConstraintOp] = None, ) -> None: self.constraint_name = constraint_name self.table_name = table_name self.constraint_type = type_ self.schema = schema self._reverse = _reverse def reverse(self) -> AddConstraintOp: return AddConstraintOp.from_constraint(self.to_constraint()) def to_diff_tuple( self, ) -> Tuple[str, SchemaItem]: if self.constraint_type == "foreignkey": return ("remove_fk", self.to_constraint()) else: return ("remove_constraint", self.to_constraint()) @classmethod def from_constraint(cls, constraint: Constraint) -> DropConstraintOp: types = { "unique_constraint": "unique", "foreign_key_constraint": "foreignkey", "primary_key_constraint": "primary", "check_constraint": "check", "column_check_constraint": "check", "table_or_column_check_constraint": "check", } constraint_table = sqla_compat._table_for_constraint(constraint) return cls( sqla_compat.constraint_name_or_none(constraint.name), constraint_table.name, schema=constraint_table.schema, type_=types[constraint.__visit_name__], _reverse=AddConstraintOp.from_constraint(constraint), ) def to_constraint(self) -> Constraint: if self._reverse is not None: constraint = self._reverse.to_constraint() constraint.name = self.constraint_name constraint_table = sqla_compat._table_for_constraint(constraint) constraint_table.name = self.table_name constraint_table.schema = self.schema return constraint else: raise ValueError( "constraint cannot be produced; " "original constraint is not present" ) @classmethod def drop_constraint( cls, operations: Operations, constraint_name: str, table_name: str, type_: Optional[str] = None, , schema: Optional[str] = None, ) -> None: r"""Drop a constraint of the given name, typically via DROP CONSTRAINT. :param constraint_name: name of the constraint. :param table_name: table name. :param type\_: optional, required on MySQL. can be 'foreignkey', 'primary', 'unique', or 'check'. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ op = cls(constraint_name, table_name, type_=type_, schema=schema) return operations.invoke(op) @classmethod def batch_drop_constraint( cls, operations: BatchOperations, constraint_name: str, type_: Optional[str] = None, ) -> None: """Issue a "drop constraint" instruction using the current batch migration context. The batch form of this call omits the ``table_name`` and ``schema`` arguments from the call. .. seealso:: :meth:`.Operations.drop_constraint` """ op = cls( constraint_name, operations.impl.table_name, type_=type_, schema=operations.impl.schema, ) return operations.invoke(op) @Operations.register_operation("create_primary_key") @BatchOperations.register_operation( "create_primary_key", "batch_create_primary_key" ) @AddConstraintOp.register_add_constraint("primary_key_constraint") class CreatePrimaryKeyOp(AddConstraintOp): """Represent a create primary key operation.""" constraint_type = "primarykey" def __init__( self, constraint_name: Optional[sqla_compat._ConstraintNameDefined], table_name: str, columns: Sequence[str], , schema: Optional[str] = None, kw: Any, ) -> None: self.constraint_name = constraint_name self.table_name = table_name self.columns = columns self.schema = schema self.kw = kw @classmethod def from_constraint(cls, constraint: Constraint) -> CreatePrimaryKeyOp: constraint_table = sqla_compat._table_for_constraint(constraint) pk_constraint = cast("PrimaryKeyConstraint", constraint) return cls( sqla_compat.constraint_name_or_none(pk_constraint.name), constraint_table.name, pk_constraint.columns.keys(), schema=constraint_table.schema, pk_constraint.dialect_kwargs, ) def to_constraint( self, migration_context: Optional[MigrationContext] = None ) -> PrimaryKeyConstraint: schema_obj = schemaobj.SchemaObjects(migration_context) return schema_obj.primary_key_constraint( self.constraint_name, self.table_name, self.columns, schema=self.schema, self.kw, ) @classmethod def create_primary_key( cls, operations: Operations, constraint_name: Optional[str], table_name: str, columns: List[str], , schema: Optional[str] = None, ) -> None: """Issue a "create primary key" instruction using the current migration context. e.g.:: from alembic import op op.create_primary_key("pk_my_table", "my_table", ["id", "version"]) This internally generates a :class:`~sqlalchemy.schema.Table` object containing the necessary columns, then generates a new :class:`~sqlalchemy.schema.PrimaryKeyConstraint` object which it then associates with the :class:`~sqlalchemy.schema.Table`. Any event listeners associated with this action will be fired off normally. The :class:`~sqlalchemy.schema.AddConstraint` construct is ultimately used to generate the ALTER statement. :param constraint_name: Name of the primary key constraint. The name is necessary so that an ALTER statement can be emitted. For setups that use an automated naming scheme such as that described at :ref:`sqla:constraint_naming_conventions` ``name`` here can be ``None``, as the event listener will apply the name to the constraint object when it is associated with the table. :param table_name: String name of the target table. :param columns: a list of string column names to be applied to the primary key constraint. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ op = cls(constraint_name, table_name, columns, schema=schema) return operations.invoke(op) @classmethod def batch_create_primary_key( cls, operations: BatchOperations, constraint_name: str, columns: List[str], ) -> None: """Issue a "create primary key" instruction using the current batch migration context. The batch form of this call omits the ``table_name`` and ``schema`` arguments from the call. .. seealso:: :meth:`.Operations.create_primary_key` """ op = cls( constraint_name, operations.impl.table_name, columns, schema=operations.impl.schema, ) return operations.invoke(op) @Operations.register_operation("create_unique_constraint") @BatchOperations.register_operation( "create_unique_constraint", "batch_create_unique_constraint" ) @AddConstraintOp.register_add_constraint("unique_constraint") class CreateUniqueConstraintOp(AddConstraintOp): """Represent a create unique constraint operation.""" constraint_type = "unique" def __init__( self, constraint_name: Optional[sqla_compat._ConstraintNameDefined], table_name: str, columns: Sequence[str], , schema: Optional[str] = None, kw: Any, ) -> None: self.constraint_name = constraint_name self.table_name = table_name self.columns = columns self.schema = schema self.kw = kw @classmethod def from_constraint( cls, constraint: Constraint ) -> CreateUniqueConstraintOp: constraint_table = sqla_compat._table_for_constraint(constraint) uq_constraint = cast("UniqueConstraint", constraint) kw: dict = {} if uq_constraint.deferrable: kw["deferrable"] = uq_constraint.deferrable if uq_constraint.initially: kw["initially"] = uq_constraint.initially kw.update(uq_constraint.dialect_kwargs) return cls( sqla_compat.constraint_name_or_none(uq_constraint.name), constraint_table.name, [c.name for c in uq_constraint.columns], schema=constraint_table.schema, kw, ) def to_constraint( self, migration_context: Optional[MigrationContext] = None ) -> UniqueConstraint: schema_obj = schemaobj.SchemaObjects(migration_context) return schema_obj.unique_constraint( self.constraint_name, self.table_name, self.columns, schema=self.schema, self.kw, ) @classmethod def create_unique_constraint( cls, operations: Operations, constraint_name: Optional[str], table_name: str, columns: Sequence[str], , schema: Optional[str] = None, kw: Any, ) -> Any: """Issue a "create unique constraint" instruction using the current migration context. e.g.:: from alembic import op op.create_unique_constraint("uq_user_name", "user", ["name"]) This internally generates a :class:`~sqlalchemy.schema.Table` object containing the necessary columns, then generates a new :class:`~sqlalchemy.schema.UniqueConstraint` object which it then associates with the :class:`~sqlalchemy.schema.Table`. Any event listeners associated with this action will be fired off normally. The :class:`~sqlalchemy.schema.AddConstraint` construct is ultimately used to generate the ALTER statement. :param name: Name of the unique constraint. The name is necessary so that an ALTER statement can be emitted. For setups that use an automated naming scheme such as that described at :ref:`sqla:constraint_naming_conventions`, ``name`` here can be ``None``, as the event listener will apply the name to the constraint object when it is associated with the table. :param table_name: String name of the source table. :param columns: a list of string column names in the source table. :param deferrable: optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when issuing DDL for this constraint. :param initially: optional string. If set, emit INITIALLY <value> when issuing DDL for this constraint. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ op = cls(constraint_name, table_name, columns, schema=schema, kw) return operations.invoke(op) @classmethod def batch_create_unique_constraint( cls, operations: BatchOperations, constraint_name: str, columns: Sequence[str], kw: Any, ) -> Any: """Issue a "create unique constraint" instruction using the current batch migration context. The batch form of this call omits the ``source`` and ``schema`` arguments from the call. .. seealso:: :meth:`.Operations.create_unique_constraint` """ kw["schema"] = operations.impl.schema op = cls(constraint_name, operations.impl.table_name, columns, kw) return operations.invoke(op) @Operations.register_operation("create_foreign_key") @BatchOperations.register_operation( "create_foreign_key", "batch_create_foreign_key" ) @AddConstraintOp.register_add_constraint("foreign_key_constraint") class CreateForeignKeyOp(AddConstraintOp): """Represent a create foreign key constraint operation.""" constraint_type = "foreignkey" def __init__( self, constraint_name: Optional[sqla_compat._ConstraintNameDefined], source_table: str, referent_table: str, local_cols: List[str], remote_cols: List[str], kw: Any, ) -> None: self.constraint_name = constraint_name self.source_table = source_table self.referent_table = referent_table self.local_cols = local_cols self.remote_cols = remote_cols self.kw = kw def to_diff_tuple(self) -> Tuple[str, ForeignKeyConstraint]: return ("add_fk", self.to_constraint()) @classmethod def from_constraint(cls, constraint: Constraint) -> CreateForeignKeyOp: fk_constraint = cast("ForeignKeyConstraint", constraint) kw: dict = {} if fk_constraint.onupdate: kw["onupdate"] = fk_constraint.onupdate if fk_constraint.ondelete: kw["ondelete"] = fk_constraint.ondelete if fk_constraint.initially: kw["initially"] = fk_constraint.initially if fk_constraint.deferrable: kw["deferrable"] = fk_constraint.deferrable if fk_constraint.use_alter: kw["use_alter"] = fk_constraint.use_alter ( source_schema, source_table, source_columns, target_schema, target_table, target_columns, onupdate, ondelete, deferrable, initially, ) = sqla_compat._fk_spec(fk_constraint) kw["source_schema"] = source_schema kw["referent_schema"] = target_schema kw.update(fk_constraint.dialect_kwargs) return cls( sqla_compat.constraint_name_or_none(fk_constraint.name), source_table, target_table, source_columns, target_columns, kw, ) def to_constraint( self, migration_context: Optional[MigrationContext] = None ) -> ForeignKeyConstraint: schema_obj = schemaobj.SchemaObjects(migration_context) return schema_obj.foreign_key_constraint( self.constraint_name, self.source_table, self.referent_table, self.local_cols, self.remote_cols, *self.kw, ) @classmethod def create_foreign_key( cls, operations: Operations, constraint_name: Optional[str], source_table: str, referent_table: str, local_cols: List[str], remote_cols: List[str], , onupdate: Optional[str] = None, ondelete: Optional[str] = None, deferrable: Optional[bool] = None, initially: Optional[str] = None, match: Optional[str] = None, source_schema: Optional[str] = None, referent_schema: Optional[str] = None, dialect_kw: Any, ) -> None: """Issue a "create foreign key" instruction using the current migration context. e.g.:: from alembic import op op.create_foreign_key( "fk_user_address", "address", "user", ["user_id"], ["id"], ) This internally generates a :class:`~sqlalchemy.schema.Table` object containing the necessary columns, then generates a new :class:`~sqlalchemy.schema.ForeignKeyConstraint` object which it then associates with the :class:`~sqlalchemy.schema.Table`. Any event listeners associated with this action will be fired off normally. The :class:`~sqlalchemy.schema.AddConstraint` construct is ultimately used to generate the ALTER statement. :param constraint_name: Name of the foreign key constraint. The name is necessary so that an ALTER statement can be emitted. For setups that use an automated naming scheme such as that described at :ref:`sqla:constraint_naming_conventions`, ``name`` here can be ``None``, as the event listener will apply the name to the constraint object when it is associated with the table. :param source_table: String name of the source table. :param referent_table: String name of the destination table. :param local_cols: a list of string column names in the source table. :param remote_cols: a list of string column names in the remote table. :param onupdate: Optional string. If set, emit ON UPDATE <value> when issuing DDL for this constraint. Typical values include CASCADE, DELETE and RESTRICT. :param ondelete: Optional string. If set, emit ON DELETE <value> when issuing DDL for this constraint. Typical values include CASCADE, DELETE and RESTRICT. :param deferrable: optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when issuing DDL for this constraint. :param source_schema: Optional schema name of the source table. :param referent_schema: Optional schema name of the destination table. """ op = cls( constraint_name, source_table, referent_table, local_cols, remote_cols, onupdate=onupdate, ondelete=ondelete, deferrable=deferrable, source_schema=source_schema, referent_schema=referent_schema, initially=initially, match=match, dialect_kw, ) return operations.invoke(op) @classmethod def batch_create_foreign_key( cls, operations: BatchOperations, constraint_name: str, referent_table: str, local_cols: List[str], remote_cols: List[str], , referent_schema: Optional[str] = None, onupdate: Optional[str] = None, ondelete: Optional[str] = None, deferrable: Optional[bool] = None, initially: Optional[str] = None, match: Optional[str] = None, dialect_kw: Any, ) -> None: """Issue a "create foreign key" instruction using the current batch migration context. The batch form of this call omits the ``source`` and ``source_schema`` arguments from the call. e.g.:: with batch_alter_table("address") as batch_op: batch_op.create_foreign_key( "fk_user_address", "user", ["user_id"], ["id"], ) .. seealso:: :meth:`.Operations.create_foreign_key` """ op = cls( constraint_name, operations.impl.table_name, referent_table, local_cols, remote_cols, onupdate=onupdate, ondelete=ondelete, deferrable=deferrable, source_schema=operations.impl.schema, referent_schema=referent_schema, initially=initially, match=match, dialect_kw, ) return operations.invoke(op) @Operations.register_operation("create_check_constraint") @BatchOperations.register_operation( "create_check_constraint", "batch_create_check_constraint" ) @AddConstraintOp.register_add_constraint("check_constraint") @AddConstraintOp.register_add_constraint("table_or_column_check_constraint") @AddConstraintOp.register_add_constraint("column_check_constraint") class CreateCheckConstraintOp(AddConstraintOp): """Represent a create check constraint operation.""" constraint_type = "check" def __init__( self, constraint_name: Optional[sqla_compat._ConstraintNameDefined], table_name: str, condition: Union[str, TextClause, ColumnElement[Any]], , schema: Optional[str] = None, kw: Any, ) -> None: self.constraint_name = constraint_name self.table_name = table_name self.condition = condition self.schema = schema self.kw = kw @classmethod def from_constraint( cls, constraint: Constraint ) -> CreateCheckConstraintOp: constraint_table = sqla_compat._table_for_constraint(constraint) ck_constraint = cast("CheckConstraint", constraint) return cls( sqla_compat.constraint_name_or_none(ck_constraint.name), constraint_table.name, cast("ColumnElement[Any]", ck_constraint.sqltext), schema=constraint_table.schema, ck_constraint.dialect_kwargs, ) def to_constraint( self, migration_context: Optional[MigrationContext] = None ) -> CheckConstraint: schema_obj = schemaobj.SchemaObjects(migration_context) return schema_obj.check_constraint( self.constraint_name, self.table_name, self.condition, schema=self.schema, *self.kw, ) @classmethod def create_check_constraint( cls, operations: Operations, constraint_name: Optional[str], table_name: str, condition: Union[str, BinaryExpression, TextClause], , schema: Optional[str] = None, kw: Any, ) -> None: """Issue a "create check constraint" instruction using the current migration context. e.g.:: from alembic import op from sqlalchemy.sql import column, func op.create_check_constraint( "ck_user_name_len", "user", func.len(column("name")) > 5, ) CHECK constraints are usually against a SQL expression, so ad-hoc table metadata is usually needed. The function will convert the given arguments into a :class:`sqlalchemy.schema.CheckConstraint` bound to an anonymous table in order to emit the CREATE statement. :param name: Name of the check constraint. The name is necessary so that an ALTER statement can be emitted. For setups that use an automated naming scheme such as that described at :ref:`sqla:constraint_naming_conventions`, ``name`` here can be ``None``, as the event listener will apply the name to the constraint object when it is associated with the table. :param table_name: String name of the source table. :param condition: SQL expression that's the condition of the constraint. Can be a string or SQLAlchemy expression language structure. :param deferrable: optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when issuing DDL for this constraint. :param initially: optional string. If set, emit INITIALLY <value> when issuing DDL for this constraint. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ op = cls(constraint_name, table_name, condition, schema=schema, kw) return operations.invoke(op) @classmethod def batch_create_check_constraint( cls, operations: BatchOperations, constraint_name: str, condition: Union[str, BinaryExpression, TextClause], kw: Any, ) -> None: """Issue a "create check constraint" instruction using the current batch migration context. The batch form of this call omits the ``source`` and ``schema`` arguments from the call. .. seealso:: :meth:`.Operations.create_check_constraint` """ op = cls( constraint_name, operations.impl.table_name, condition, schema=operations.impl.schema, kw, ) return operations.invoke(op) @Operations.register_operation("create_index") @BatchOperations.register_operation("create_index", "batch_create_index") class CreateIndexOp(MigrateOperation): """Represent a create index operation.""" def __init__( self, index_name: Optional[str], table_name: str, columns: Sequence[Union[str, TextClause, ColumnElement[Any]]], , schema: Optional[str] = None, unique: bool = False, kw: Any, ) -> None: self.index_name = index_name self.table_name = table_name self.columns = columns self.schema = schema self.unique = unique self.kw = kw def reverse(self) -> DropIndexOp: return DropIndexOp.from_index(self.to_index()) def to_diff_tuple(self) -> Tuple[str, Index]: return ("add_index", self.to_index()) @classmethod def from_index(cls, index: Index) -> CreateIndexOp: assert index.table is not None return cls( index.name, # type: ignore[arg-type] index.table.name, sqla_compat._get_index_expressions(index), schema=index.table.schema, unique=index.unique, index.kwargs, ) def to_index( self, migration_context: Optional[MigrationContext] = None ) -> Index: schema_obj = schemaobj.SchemaObjects(migration_context) idx = schema_obj.index( self.index_name, self.table_name, self.columns, schema=self.schema, unique=self.unique, self.kw, ) return idx @classmethod def create_index( cls, operations: Operations, index_name: Optional[str], table_name: str, columns: Sequence[Union[str, TextClause, Function[Any]]], , schema: Optional[str] = None, unique: bool = False, kw: Any, ) -> None: r"""Issue a "create index" instruction using the current migration context. e.g.:: from alembic import op op.create_index("ik_test", "t1", ["foo", "bar"]) Functional indexes can be produced by using the :func:`sqlalchemy.sql.expression.text` construct:: from alembic import op from sqlalchemy import text op.create_index("ik_test", "t1", [text("lower(foo)")]) :param index_name: name of the index. :param table_name: name of the owning table. :param columns: a list consisting of string column names and/or :func:`~sqlalchemy.sql.expression.text` constructs. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param unique: If True, create a unique index. :param quote: Force quoting of this column's name on or off, corresponding to ``True`` or ``False``. When left at its default of ``None``, the column identifier will be quoted according to whether the name is case sensitive (identifiers with at least one upper case character are treated as case sensitive), or if it's a reserved word. This flag is only needed to force quoting of a reserved word which is not known by the SQLAlchemy dialect. :param \kw: Additional keyword arguments not mentioned above are dialect specific, and passed in the form ``<dialectname>_<argname>``. See the documentation regarding an individual dialect at :ref:`dialect_toplevel` for detail on documented arguments. """ op = cls( index_name, table_name, columns, schema=schema, unique=unique, kw ) return operations.invoke(op) @classmethod def batch_create_index( cls, operations: BatchOperations, index_name: str, columns: List[str], kw: Any, ) -> None: """Issue a "create index" instruction using the current batch migration context. .. seealso:: :meth:`.Operations.create_index` """ op = cls( index_name, operations.impl.table_name, columns, schema=operations.impl.schema, *kw, ) return operations.invoke(op) @Operations.register_operation("drop_index") @BatchOperations.register_operation("drop_index", "batch_drop_index") class DropIndexOp(MigrateOperation): """Represent a drop index operation.""" def __init__( self, index_name: Union[quoted_name, str, conv], table_name: Optional[str] = None, , schema: Optional[str] = None, _reverse: Optional[CreateIndexOp] = None, kw: Any, ) -> None: self.index_name = index_name self.table_name = table_name self.schema = schema self._reverse = _reverse self.kw = kw def to_diff_tuple(self) -> Tuple[str, Index]: return ("remove_index", self.to_index()) def reverse(self) -> CreateIndexOp: return CreateIndexOp.from_index(self.to_index()) @classmethod def from_index(cls, index: Index) -> DropIndexOp: assert index.table is not None return cls( index.name, # type: ignore[arg-type] table_name=index.table.name, schema=index.table.schema, _reverse=CreateIndexOp.from_index(index), index.kwargs, ) def to_index( self, migration_context: Optional[MigrationContext] = None ) -> Index: schema_obj = schemaobj.SchemaObjects(migration_context) # need a dummy column name here since SQLAlchemy # 0.7.6 and further raises on Index with no columns return schema_obj.index( self.index_name, self.table_name, self._reverse.columns if self._reverse else ["x"], schema=self.schema, *self.kw, ) @classmethod def drop_index( cls, operations: Operations, index_name: str, table_name: Optional[str] = None, , schema: Optional[str] = None, kw: Any, ) -> None: r"""Issue a "drop index" instruction using the current migration context. e.g.:: drop_index("accounts") :param index_name: name of the index. :param table_name: name of the owning table. Some backends such as Microsoft SQL Server require this. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param \kw: Additional keyword arguments not mentioned above are dialect specific, and passed in the form ``<dialectname>_<argname>``. See the documentation regarding an individual dialect at :ref:`dialect_toplevel` for detail on documented arguments. """ op = cls(index_name, table_name=table_name, schema=schema, kw) return operations.invoke(op) @classmethod def batch_drop_index( cls, operations: BatchOperations, index_name: str, kw: Any ) -> None: """Issue a "drop index" instruction using the current batch migration context. .. seealso:: :meth:`.Operations.drop_index` """ op = cls( index_name, table_name=operations.impl.table_name, schema=operations.impl.schema, *kw, ) return operations.invoke(op) @Operations.register_operation("create_table") class CreateTableOp(MigrateOperation): """Represent a create table operation.""" def __init__( self, table_name: str, columns: Sequence[SchemaItem], , schema: Optional[str] = None, _namespace_metadata: Optional[MetaData] = None, _constraints_included: bool = False, *kw: Any, ) -> None: self.table_name = table_name self.columns = columns self.schema = schema self.info = kw.pop("info", {}) self.comment = kw.pop("comment", None) self.prefixes = kw.pop("prefixes", None) self.kw = kw self._namespace_metadata = _namespace_metadata self._constraints_included = _constraints_included def reverse(self) -> DropTableOp: return DropTableOp.from_table( self.to_table(), _namespace_metadata=self._namespace_metadata ) def to_diff_tuple(self) -> Tuple[str, Table]: return ("add_table", self.to_table()) @classmethod def from_table( cls, table: Table, , _namespace_metadata: Optional[MetaData] = None ) -> CreateTableOp: if _namespace_metadata is None: _namespace_metadata = table.metadata return cls( table.name, list(table.c) + list(table.constraints), # type:ignore[arg-type] schema=table.schema, _namespace_metadata=_namespace_metadata, # given a Table() object, this Table will contain full Index() # and UniqueConstraint objects already constructed in response to # each unique=True / index=True flag on a Column. Carry this # state along so that when we re-convert back into a Table, we # skip unique=True/index=True so that these constraints are # not doubled up. see #844 #848 _constraints_included=True, comment=table.comment, info=dict(table.info), prefixes=list(table._prefixes), *table.kwargs, ) def to_table( self, migration_context: Optional[MigrationContext] = None ) -> Table: schema_obj = schemaobj.SchemaObjects(migration_context) return schema_obj.table( self.table_name, self.columns, schema=self.schema, prefixes=list(self.prefixes) if self.prefixes else [], comment=self.comment, info=self.info.copy() if self.info else {}, _constraints_included=self._constraints_included, *self.kw, ) @classmethod def create_table( cls, operations: Operations, table_name: str, columns: SchemaItem, *kw: Any, ) -> Table: r"""Issue a "create table" instruction using the current migration context. This directive receives an argument list similar to that of the traditional :class:`sqlalchemy.schema.Table` construct, but without the metadata:: from sqlalchemy import INTEGER, VARCHAR, NVARCHAR, Column from alembic import op op.create_table( "account", Column("id", INTEGER, primary_key=True), Column("name", VARCHAR(50), nullable=False), Column("description", NVARCHAR(200)), Column("timestamp", TIMESTAMP, server_default=func.now()), ) Note that :meth:`.create_table` accepts :class:`~sqlalchemy.schema.Column` constructs directly from the SQLAlchemy library. In particular, default values to be created on the database side are specified using the ``server_default`` parameter, and not ``default`` which only specifies Python-side defaults:: from alembic import op from sqlalchemy import Column, TIMESTAMP, func # specify "DEFAULT NOW" along with the "timestamp" column op.create_table( "account", Column("id", INTEGER, primary_key=True), Column("timestamp", TIMESTAMP, server_default=func.now()), ) The function also returns a newly created :class:`~sqlalchemy.schema.Table` object, corresponding to the table specification given, which is suitable for immediate SQL operations, in particular :meth:`.Operations.bulk_insert`:: from sqlalchemy import INTEGER, VARCHAR, NVARCHAR, Column from alembic import op account_table = op.create_table( "account", Column("id", INTEGER, primary_key=True), Column("name", VARCHAR(50), nullable=False), Column("description", NVARCHAR(200)), Column("timestamp", TIMESTAMP, server_default=func.now()), ) op.bulk_insert( account_table, [ {"name": "A1", "description": "account 1"}, {"name": "A2", "description": "account 2"}, ], ) :param table_name: Name of the table :param \columns: collection of :class:`~sqlalchemy.schema.Column` objects within the table, as well as optional :class:`~sqlalchemy.schema.Constraint` objects and :class:`~.sqlalchemy.schema.Index` objects. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param \kw: Other keyword arguments are passed to the underlying :class:`sqlalchemy.schema.Table` object created for the command. :return: the :class:`~sqlalchemy.schema.Table` object corresponding to the parameters given. """ op = cls(table_name, columns, kw) return operations.invoke(op) @Operations.register_operation("drop_table") class DropTableOp(MigrateOperation): """Represent a drop table operation.""" def __init__( self, table_name: str, , schema: Optional[str] = None, table_kw: Optional[MutableMapping[Any, Any]] = None, _reverse: Optional[CreateTableOp] = None, ) -> None: self.table_name = table_name self.schema = schema self.table_kw = table_kw or {} self.comment = self.table_kw.pop("comment", None) self.info = self.table_kw.pop("info", None) self.prefixes = self.table_kw.pop("prefixes", None) self._reverse = _reverse def to_diff_tuple(self) -> Tuple[str, Table]: return ("remove_table", self.to_table()) def reverse(self) -> CreateTableOp: return CreateTableOp.from_table(self.to_table()) @classmethod def from_table( cls, table: Table, , _namespace_metadata: Optional[MetaData] = None ) -> DropTableOp: return cls( table.name, schema=table.schema, table_kw={ "comment": table.comment, "info": dict(table.info), "prefixes": list(table._prefixes), *table.kwargs, }, _reverse=CreateTableOp.from_table( table, _namespace_metadata=_namespace_metadata ), ) def to_table( self, migration_context: Optional[MigrationContext] = None ) -> Table: if self._reverse: cols_and_constraints = self._reverse.columns else: cols_and_constraints = [] schema_obj = schemaobj.SchemaObjects(migration_context) t = schema_obj.table( self.table_name, cols_and_constraints, comment=self.comment, info=self.info.copy() if self.info else {}, prefixes=list(self.prefixes) if self.prefixes else [], schema=self.schema, _constraints_included=self._reverse._constraints_included if self._reverse else False, *self.table_kw, ) return t @classmethod def drop_table( cls, operations: Operations, table_name: str, , schema: Optional[str] = None, kw: Any, ) -> None: r"""Issue a "drop table" instruction using the current migration context. e.g.:: drop_table("accounts") :param table_name: Name of the table :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param \kw: Other keyword arguments are passed to the underlying :class:`sqlalchemy.schema.Table` object created for the command. """ op = cls(table_name, schema=schema, table_kw=kw) operations.invoke(op) class AlterTableOp(MigrateOperation): """Represent an alter table operation.""" def __init__( self, table_name: str, , schema: Optional[str] = None, ) -> None: self.table_name = table_name self.schema = schema @Operations.register_operation("rename_table") class RenameTableOp(AlterTableOp): """Represent a rename table operation.""" def __init__( self, old_table_name: str, new_table_name: str, , schema: Optional[str] = None, ) -> None: super().__init__(old_table_name, schema=schema) self.new_table_name = new_table_name @classmethod def rename_table( cls, operations: Operations, old_table_name: str, new_table_name: str, , schema: Optional[str] = None, ) -> None: """Emit an ALTER TABLE to rename a table. :param old_table_name: old name. :param new_table_name: new name. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ op = cls(old_table_name, new_table_name, schema=schema) return operations.invoke(op) @Operations.register_operation("create_table_comment") @BatchOperations.register_operation( "create_table_comment", "batch_create_table_comment" ) class CreateTableCommentOp(AlterTableOp): """Represent a COMMENT ON `table` operation.""" def __init__( self, table_name: str, comment: Optional[str], , schema: Optional[str] = None, existing_comment: Optional[str] = None, ) -> None: self.table_name = table_name self.comment = comment self.existing_comment = existing_comment self.schema = schema @classmethod def create_table_comment( cls, operations: Operations, table_name: str, comment: Optional[str], , existing_comment: Optional[str] = None, schema: Optional[str] = None, ) -> None: """Emit a COMMENT ON operation to set the comment for a table. .. versionadded:: 1.0.6 :param table_name: string name of the target table. :param comment: string value of the comment being registered against the specified table. :param existing_comment: String value of a comment already registered on the specified table, used within autogenerate so that the operation is reversible, but not required for direct use. .. seealso:: :meth:`.Operations.drop_table_comment` :paramref:`.Operations.alter_column.comment` """ op = cls( table_name, comment, existing_comment=existing_comment, schema=schema, ) return operations.invoke(op) @classmethod def batch_create_table_comment( cls, operations: BatchOperations, comment: Optional[str], , existing_comment: Optional[str] = None, ) -> None: """Emit a COMMENT ON operation to set the comment for a table using the current batch migration context. .. versionadded:: 1.6.0 :param comment: string value of the comment being registered against the specified table. :param existing_comment: String value of a comment already registered on the specified table, used within autogenerate so that the operation is reversible, but not required for direct use. """ op = cls( operations.impl.table_name, comment, existing_comment=existing_comment, schema=operations.impl.schema, ) return operations.invoke(op) def reverse(self): """Reverses the COMMENT ON operation against a table.""" if self.existing_comment is None: return DropTableCommentOp( self.table_name, existing_comment=self.comment, schema=self.schema, ) else: return CreateTableCommentOp( self.table_name, self.existing_comment, existing_comment=self.comment, schema=self.schema, ) def to_table(self, migration_context=None): schema_obj = schemaobj.SchemaObjects(migration_context) return schema_obj.table( self.table_name, schema=self.schema, comment=self.comment ) def to_diff_tuple(self): return ("add_table_comment", self.to_table(), self.existing_comment) @Operations.register_operation("drop_table_comment") @BatchOperations.register_operation( "drop_table_comment", "batch_drop_table_comment" ) class DropTableCommentOp(AlterTableOp): """Represent an operation to remove the comment from a table.""" def __init__( self, table_name: str, , schema: Optional[str] = None, existing_comment: Optional[str] = None, ) -> None: self.table_name = table_name self.existing_comment = existing_comment self.schema = schema @classmethod def drop_table_comment( cls, operations: Operations, table_name: str, , existing_comment: Optional[str] = None, schema: Optional[str] = None, ) -> None: """Issue a "drop table comment" operation to remove an existing comment set on a table. .. versionadded:: 1.0.6 :param table_name: string name of the target table. :param existing_comment: An optional string value of a comment already registered on the specified table. .. seealso:: :meth:`.Operations.create_table_comment` :paramref:`.Operations.alter_column.comment` """ op = cls(table_name, existing_comment=existing_comment, schema=schema) return operations.invoke(op) @classmethod def batch_drop_table_comment( cls, operations: BatchOperations, , existing_comment: Optional[str] = None, ) -> None: """Issue a "drop table comment" operation to remove an existing comment set on a table using the current batch operations context. .. versionadded:: 1.6.0 :param existing_comment: An optional string value of a comment already registered on the specified table. """ op = cls( operations.impl.table_name, existing_comment=existing_comment, schema=operations.impl.schema, ) return operations.invoke(op) def reverse(self): """Reverses the COMMENT ON operation against a table.""" return CreateTableCommentOp( self.table_name, self.existing_comment, schema=self.schema ) def to_table(self, migration_context=None): schema_obj = schemaobj.SchemaObjects(migration_context) return schema_obj.table(self.table_name, schema=self.schema) def to_diff_tuple(self): return ("remove_table_comment", self.to_table()) @Operations.register_operation("alter_column") @BatchOperations.register_operation("alter_column", "batch_alter_column") class AlterColumnOp(AlterTableOp): """Represent an alter column operation.""" def __init__( self, table_name: str, column_name: str, , schema: Optional[str] = None, existing_type: Optional[Any] = None, existing_server_default: Any = False, existing_nullable: Optional[bool] = None, existing_comment: Optional[str] = None, modify_nullable: Optional[bool] = None, modify_comment: Optional[Union[str, Literal[False]]] = False, modify_server_default: Any = False, modify_name: Optional[str] = None, modify_type: Optional[Any] = None, kw: Any, ) -> None: super().__init__(table_name, schema=schema) self.column_name = column_name self.existing_type = existing_type self.existing_server_default = existing_server_default self.existing_nullable = existing_nullable self.existing_comment = existing_comment self.modify_nullable = modify_nullable self.modify_comment = modify_comment self.modify_server_default = modify_server_default self.modify_name = modify_name self.modify_type = modify_type self.kw = kw def to_diff_tuple(self) -> Any: col_diff = [] schema, tname, cname = self.schema, self.table_name, self.column_name if self.modify_type is not None: col_diff.append( ( "modify_type", schema, tname, cname, { "existing_nullable": self.existing_nullable, "existing_server_default": ( self.existing_server_default ), "existing_comment": self.existing_comment, }, self.existing_type, self.modify_type, ) ) if self.modify_nullable is not None: col_diff.append( ( "modify_nullable", schema, tname, cname, { "existing_type": self.existing_type, "existing_server_default": ( self.existing_server_default ), "existing_comment": self.existing_comment, }, self.existing_nullable, self.modify_nullable, ) ) if self.modify_server_default is not False: col_diff.append( ( "modify_default", schema, tname, cname, { "existing_nullable": self.existing_nullable, "existing_type": self.existing_type, "existing_comment": self.existing_comment, }, self.existing_server_default, self.modify_server_default, ) ) if self.modify_comment is not False: col_diff.append( ( "modify_comment", schema, tname, cname, { "existing_nullable": self.existing_nullable, "existing_type": self.existing_type, "existing_server_default": ( self.existing_server_default ), }, self.existing_comment, self.modify_comment, ) ) return col_diff def has_changes(self) -> bool: hc1 = ( self.modify_nullable is not None or self.modify_server_default is not False or self.modify_type is not None or self.modify_comment is not False ) if hc1: return True for kw in self.kw: if kw.startswith("modify_"): return True else: return False def reverse(self) -> AlterColumnOp: kw = self.kw.copy() kw["existing_type"] = self.existing_type kw["existing_nullable"] = self.existing_nullable kw["existing_server_default"] = self.existing_server_default kw["existing_comment"] = self.existing_comment if self.modify_type is not None: kw["modify_type"] = self.modify_type if self.modify_nullable is not None: kw["modify_nullable"] = self.modify_nullable if self.modify_server_default is not False: kw["modify_server_default"] = self.modify_server_default if self.modify_comment is not False: kw["modify_comment"] = self.modify_comment # TODO: make this a little simpler all_keys = { m.group(1) for m in [re.match(r"^(?:existing_\|modify_)(.+)$", k) for k in kw] if m } for k in all_keys: if "modify_%s" % k in kw: swap = kw["existing_%s" % k] kw["existing_%s" % k] = kw["modify_%s" % k] kw["modify_%s" % k] = swap return self.__class__( self.table_name, self.column_name, schema=self.schema, kw ) @classmethod def alter_column( cls, operations: Operations, table_name: str, column_name: str, , nullable: Optional[bool] = None, comment: Optional[Union[str, Literal[False]]] = False, server_default: Any = False, new_column_name: Optional[str] = None, type_: Optional[Union[TypeEngine, Type[TypeEngine]]] = None, existing_type: Optional[Union[TypeEngine, Type[TypeEngine]]] = None, existing_server_default: Optional[ Union[str, bool, Identity, Computed] ] = False, existing_nullable: Optional[bool] = None, existing_comment: Optional[str] = None, schema: Optional[str] = None, kw: Any, ) -> None: r"""Issue an "alter column" instruction using the current migration context. Generally, only that aspect of the column which is being changed, i.e. name, type, nullability, default, needs to be specified. Multiple changes can also be specified at once and the backend should "do the right thing", emitting each change either separately or together as the backend allows. MySQL has special requirements here, since MySQL cannot ALTER a column without a full specification. When producing MySQL-compatible migration files, it is recommended that the ``existing_type``, ``existing_server_default``, and ``existing_nullable`` parameters be present, if not being altered. Type changes which are against the SQLAlchemy "schema" types :class:`~sqlalchemy.types.Boolean` and :class:`~sqlalchemy.types.Enum` may also add or drop constraints which accompany those types on backends that don't support them natively. The ``existing_type`` argument is used in this case to identify and remove a previous constraint that was bound to the type object. :param table_name: string name of the target table. :param column_name: string name of the target column, as it exists before the operation begins. :param nullable: Optional; specify ``True`` or ``False`` to alter the column's nullability. :param server_default: Optional; specify a string SQL expression, :func:`~sqlalchemy.sql.expression.text`, or :class:`~sqlalchemy.schema.DefaultClause` to indicate an alteration to the column's default value. Set to ``None`` to have the default removed. :param comment: optional string text of a new comment to add to the column. .. versionadded:: 1.0.6 :param new_column_name: Optional; specify a string name here to indicate the new name within a column rename operation. :param type\_: Optional; a :class:`~sqlalchemy.types.TypeEngine` type object to specify a change to the column's type. For SQLAlchemy types that also indicate a constraint (i.e. :class:`~sqlalchemy.types.Boolean`, :class:`~sqlalchemy.types.Enum`), the constraint is also generated. :param autoincrement: set the ``AUTO_INCREMENT`` flag of the column; currently understood by the MySQL dialect. :param existing_type: Optional; a :class:`~sqlalchemy.types.TypeEngine` type object to specify the previous type. This is required for all MySQL column alter operations that don't otherwise specify a new type, as well as for when nullability is being changed on a SQL Server column. It is also used if the type is a so-called SQLlchemy "schema" type which may define a constraint (i.e. :class:`~sqlalchemy.types.Boolean`, :class:`~sqlalchemy.types.Enum`), so that the constraint can be dropped. :param existing_server_default: Optional; The existing default value of the column. Required on MySQL if an existing default is not being changed; else MySQL removes the default. :param existing_nullable: Optional; the existing nullability of the column. Required on MySQL if the existing nullability is not being changed; else MySQL sets this to NULL. :param existing_autoincrement: Optional; the existing autoincrement of the column. Used for MySQL's system of altering a column that specifies ``AUTO_INCREMENT``. :param existing_comment: string text of the existing comment on the column to be maintained. Required on MySQL if the existing comment on the column is not being changed. .. versionadded:: 1.0.6 :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param postgresql_using: String argument which will indicate a SQL expression to render within the Postgresql-specific USING clause within ALTER COLUMN. This string is taken directly as raw SQL which must explicitly include any necessary quoting or escaping of tokens within the expression. """ alt = cls( table_name, column_name, schema=schema, existing_type=existing_type, existing_server_default=existing_server_default, existing_nullable=existing_nullable, existing_comment=existing_comment, modify_name=new_column_name, modify_type=type_, modify_server_default=server_default, modify_nullable=nullable, modify_comment=comment, kw, ) return operations.invoke(alt) @classmethod def batch_alter_column( cls, operations: BatchOperations, column_name: str, , nullable: Optional[bool] = None, comment: Optional[Union[str, Literal[False]]] = False, server_default: Any = False, new_column_name: Optional[str] = None, type_: Optional[Union[TypeEngine, Type[TypeEngine]]] = None, existing_type: Optional[Union[TypeEngine, Type[TypeEngine]]] = None, existing_server_default: Optional[ Union[str, bool, Identity, Computed] ] = False, existing_nullable: Optional[bool] = None, existing_comment: Optional[str] = None, insert_before: Optional[str] = None, insert_after: Optional[str] = None, kw: Any, ) -> None: """Issue an "alter column" instruction using the current batch migration context. Parameters are the same as that of :meth:`.Operations.alter_column`, as well as the following option(s): :param insert_before: String name of an existing column which this column should be placed before, when creating the new table. .. versionadded:: 1.4.0 :param insert_after: String name of an existing column which this column should be placed after, when creating the new table. If both :paramref:`.BatchOperations.alter_column.insert_before` and :paramref:`.BatchOperations.alter_column.insert_after` are omitted, the column is inserted after the last existing column in the table. .. versionadded:: 1.4.0 .. seealso:: :meth:`.Operations.alter_column` """ alt = cls( operations.impl.table_name, column_name, schema=operations.impl.schema, existing_type=existing_type, existing_server_default=existing_server_default, existing_nullable=existing_nullable, existing_comment=existing_comment, modify_name=new_column_name, modify_type=type_, modify_server_default=server_default, modify_nullable=nullable, modify_comment=comment, insert_before=insert_before, insert_after=insert_after, kw, ) return operations.invoke(alt) @Operations.register_operation("add_column") @BatchOperations.register_operation("add_column", "batch_add_column") class AddColumnOp(AlterTableOp): """Represent an add column operation.""" def __init__( self, table_name: str, column: Column[Any], , schema: Optional[str] = None, kw: Any, ) -> None: super().__init__(table_name, schema=schema) self.column = column self.kw = kw def reverse(self) -> DropColumnOp: return DropColumnOp.from_column_and_tablename( self.schema, self.table_name, self.column ) def to_diff_tuple( self, ) -> Tuple[str, Optional[str], str, Column[Any]]: return ("add_column", self.schema, self.table_name, self.column) def to_column(self) -> Column: return self.column @classmethod def from_column(cls, col: Column) -> AddColumnOp: return cls(col.table.name, col, schema=col.table.schema) @classmethod def from_column_and_tablename( cls, schema: Optional[str], tname: str, col: Column[Any], ) -> AddColumnOp: return cls(tname, col, schema=schema) @classmethod def add_column( cls, operations: Operations, table_name: str, column: Column[Any], , schema: Optional[str] = None, ) -> None: """Issue an "add column" instruction using the current migration context. e.g.:: from alembic import op from sqlalchemy import Column, String op.add_column("organization", Column("name", String())) The :meth:`.Operations.add_column` method typically corresponds to the SQL command "ALTER TABLE... ADD COLUMN". Within the scope of this command, the column's name, datatype, nullability, and optional server-generated defaults may be indicated. .. note:: With the exception of NOT NULL constraints or single-column FOREIGN KEY constraints, other kinds of constraints such as PRIMARY KEY, UNIQUE or CHECK constraints cannot be generated using this method; for these constraints, refer to operations such as :meth:`.Operations.create_primary_key` and :meth:`.Operations.create_check_constraint`. In particular, the following :class:`~sqlalchemy.schema.Column` parameters are ignored: * :paramref:`~sqlalchemy.schema.Column.primary_key` - SQL databases typically do not support an ALTER operation that can add individual columns one at a time to an existing primary key constraint, therefore it's less ambiguous to use the :meth:`.Operations.create_primary_key` method, which assumes no existing primary key constraint is present. * :paramref:`~sqlalchemy.schema.Column.unique` - use the :meth:`.Operations.create_unique_constraint` method * :paramref:`~sqlalchemy.schema.Column.index` - use the :meth:`.Operations.create_index` method The provided :class:`~sqlalchemy.schema.Column` object may include a :class:`~sqlalchemy.schema.ForeignKey` constraint directive, referencing a remote table name. For this specific type of constraint, Alembic will automatically emit a second ALTER statement in order to add the single-column FOREIGN KEY constraint separately:: from alembic import op from sqlalchemy import Column, INTEGER, ForeignKey op.add_column( "organization", Column("account_id", INTEGER, ForeignKey("accounts.id")), ) The column argument passed to :meth:`.Operations.add_column` is a :class:`~sqlalchemy.schema.Column` construct, used in the same way it's used in SQLAlchemy. In particular, values or functions to be indicated as producing the column's default value on the database side are specified using the ``server_default`` parameter, and not ``default`` which only specifies Python-side defaults:: from alembic import op from sqlalchemy import Column, TIMESTAMP, func # specify "DEFAULT NOW" along with the column add op.add_column( "account", Column("timestamp", TIMESTAMP, server_default=func.now()), ) :param table_name: String name of the parent table. :param column: a :class:`sqlalchemy.schema.Column` object representing the new column. :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. """ op = cls(table_name, column, schema=schema) return operations.invoke(op) @classmethod def batch_add_column( cls, operations: BatchOperations, column: Column[Any], , insert_before: Optional[str] = None, insert_after: Optional[str] = None, ) -> None: """Issue an "add column" instruction using the current batch migration context. .. seealso:: :meth:`.Operations.add_column` """ kw = {} if insert_before: kw["insert_before"] = insert_before if insert_after: kw["insert_after"] = insert_after op = cls( operations.impl.table_name, column, schema=operations.impl.schema, kw, ) return operations.invoke(op) @Operations.register_operation("drop_column") @BatchOperations.register_operation("drop_column", "batch_drop_column") class DropColumnOp(AlterTableOp): """Represent a drop column operation.""" def __init__( self, table_name: str, column_name: str, , schema: Optional[str] = None, _reverse: Optional[AddColumnOp] = None, *kw: Any, ) -> None: super().__init__(table_name, schema=schema) self.column_name = column_name self.kw = kw self._reverse = _reverse def to_diff_tuple( self, ) -> Tuple[str, Optional[str], str, Column[Any]]: return ( "remove_column", self.schema, self.table_name, self.to_column(), ) def reverse(self) -> AddColumnOp: if self._reverse is None: raise ValueError( "operation is not reversible; " "original column is not present" ) return AddColumnOp.from_column_and_tablename( self.schema, self.table_name, self._reverse.column ) @classmethod def from_column_and_tablename( cls, schema: Optional[str], tname: str, col: Column[Any], ) -> DropColumnOp: return cls( tname, col.name, schema=schema, _reverse=AddColumnOp.from_column_and_tablename(schema, tname, col), ) def to_column( self, migration_context: Optional[MigrationContext] = None ) -> Column: if self._reverse is not None: return self._reverse.column schema_obj = schemaobj.SchemaObjects(migration_context) return schema_obj.column(self.column_name, NULLTYPE) @classmethod def drop_column( cls, operations: Operations, table_name: str, column_name: str, , schema: Optional[str] = None, kw: Any, ) -> None: """Issue a "drop column" instruction using the current migration context. e.g.:: drop_column("organization", "account_id") :param table_name: name of table :param column_name: name of column :param schema: Optional schema name to operate within. To control quoting of the schema outside of the default behavior, use the SQLAlchemy construct :class:`~sqlalchemy.sql.elements.quoted_name`. :param mssql_drop_check: Optional boolean. When ``True``, on Microsoft SQL Server only, first drop the CHECK constraint on the column using a SQL-script-compatible block that selects into a @variable from sys.check_constraints, then exec's a separate DROP CONSTRAINT for that constraint. :param mssql_drop_default: Optional boolean. When ``True``, on Microsoft SQL Server only, first drop the DEFAULT constraint on the column using a SQL-script-compatible block that selects into a @variable from sys.default_constraints, then exec's a separate DROP CONSTRAINT for that default. :param mssql_drop_foreign_key: Optional boolean. When ``True``, on Microsoft SQL Server only, first drop a single FOREIGN KEY constraint on the column using a SQL-script-compatible block that selects into a @variable from sys.foreign_keys/sys.foreign_key_columns, then exec's a separate DROP CONSTRAINT for that default. Only works if the column has exactly one FK constraint which refers to it, at the moment. """ op = cls(table_name, column_name, schema=schema, kw) return operations.invoke(op) @classmethod def batch_drop_column( cls, operations: BatchOperations, column_name: str, kw: Any ) -> None: """Issue a "drop column" instruction using the current batch migration context. .. seealso:: :meth:`.Operations.drop_column` """ op = cls( operations.impl.table_name, column_name, schema=operations.impl.schema, kw, ) return operations.invoke(op) @Operations.register_operation("bulk_insert") class BulkInsertOp(MigrateOperation): """Represent a bulk insert operation.""" def __init__( self, table: Union[Table, TableClause], rows: List[dict], , multiinsert: bool = True, ) -> None: self.table = table self.rows = rows self.multiinsert = multiinsert @classmethod def bulk_insert( cls, operations: Operations, table: Union[Table, TableClause], rows: List[dict], , multiinsert: bool = True, ) -> None: """Issue a "bulk insert" operation using the current migration context. This provides a means of representing an INSERT of multiple rows which works equally well in the context of executing on a live connection as well as that of generating a SQL script. In the case of a SQL script, the values are rendered inline into the statement. e.g.:: from alembic import op from datetime import date from sqlalchemy.sql import table, column from sqlalchemy import String, Integer, Date # Create an ad-hoc table to use for the insert statement. accounts_table = table( "account", column("id", Integer), column("name", String), column("create_date", Date), ) op.bulk_insert( accounts_table, [ { "id": 1, "name": "John Smith", "create_date": date(2010, 10, 5), }, { "id": 2, "name": "Ed Williams", "create_date": date(2007, 5, 27), }, { "id": 3, "name": "Wendy Jones", "create_date": date(2008, 8, 15), }, ], ) When using --sql mode, some datatypes may not render inline automatically, such as dates and other special types. When this issue is present, :meth:`.Operations.inline_literal` may be used:: op.bulk_insert( accounts_table, [ { "id": 1, "name": "John Smith", "create_date": op.inline_literal("2010-10-05"), }, { "id": 2, "name": "Ed Williams", "create_date": op.inline_literal("2007-05-27"), }, { "id": 3, "name": "Wendy Jones", "create_date": op.inline_literal("2008-08-15"), }, ], multiinsert=False, ) When using :meth:`.Operations.inline_literal` in conjunction with :meth:`.Operations.bulk_insert`, in order for the statement to work in "online" (e.g. non --sql) mode, the :paramref:`~.Operations.bulk_insert.multiinsert` flag should be set to ``False``, which will have the effect of individual INSERT statements being emitted to the database, each with a distinct VALUES clause, so that the "inline" values can still be rendered, rather than attempting to pass the values as bound parameters. :param table: a table object which represents the target of the INSERT. :param rows: a list of dictionaries indicating rows. :param multiinsert: when at its default of True and --sql mode is not enabled, the INSERT statement will be executed using "executemany()" style, where all elements in the list of dictionaries are passed as bound parameters in a single list. Setting this to False results in individual INSERT statements being emitted per parameter set, and is needed in those cases where non-literal values are present in the parameter sets. """ op = cls(table, rows, multiinsert=multiinsert) operations.invoke(op) @Operations.register_operation("execute") @BatchOperations.register_operation("execute", "batch_execute") class ExecuteSQLOp(MigrateOperation): """Represent an execute SQL operation.""" def __init__( self, sqltext: Union[Update, str, Insert, TextClause], , execution_options: Optional[dict[str, Any]] = None, ) -> None: self.sqltext = sqltext self.execution_options = execution_options @classmethod def execute( cls, operations: Operations, sqltext: Union[str, TextClause, Update], , execution_options: Optional[dict[str, Any]] = None, ) -> None: r"""Execute the given SQL using the current migration context. The given SQL can be a plain string, e.g.:: op.execute("INSERT INTO table (foo) VALUES ('some value')") Or it can be any kind of Core SQL Expression construct, such as below where we use an update construct:: from sqlalchemy.sql import table, column from sqlalchemy import String from alembic import op account = table("account", column("name", String)) op.execute( account.update() .where(account.c.name == op.inline_literal("account 1")) .values({"name": op.inline_literal("account 2")}) ) Above, we made use of the SQLAlchemy :func:`sqlalchemy.sql.expression.table` and :func:`sqlalchemy.sql.expression.column` constructs to make a brief, ad-hoc table construct just for our UPDATE statement. A full :class:`~sqlalchemy.schema.Table` construct of course works perfectly fine as well, though note it's a recommended practice to at least ensure the definition of a table is self-contained within the migration script, rather than imported from a module that may break compatibility with older migrations. In a SQL script context, the statement is emitted directly to the output stream. There is no return result, however, as this function is oriented towards generating a change script that can run in "offline" mode. Additionally, parameterized statements are discouraged here, as they will not work in offline mode. Above, we use :meth:`.inline_literal` where parameters are to be used. For full interaction with a connected database where parameters can also be used normally, use the "bind" available from the context:: from alembic import op connection = op.get_bind() connection.execute( account.update() .where(account.c.name == "account 1") .values({"name": "account 2"}) ) Additionally, when passing the statement as a plain string, it is first coerceed into a :func:`sqlalchemy.sql.expression.text` construct before being passed along. In the less likely case that the literal SQL string contains a colon, it must be escaped with a backslash, as:: op.execute(r"INSERT INTO table (foo) VALUES ('\:colon_value')") :param sqltext: Any legal SQLAlchemy expression, including: * a string * a :func:`sqlalchemy.sql.expression.text` construct. * a :func:`sqlalchemy.sql.expression.insert` construct. * a :func:`sqlalchemy.sql.expression.update`, :func:`sqlalchemy.sql.expression.insert`, or :func:`sqlalchemy.sql.expression.delete` construct. * Any "executable" described in SQLAlchemy Core documentation, noting that no result set is returned. .. note:: when passing a plain string, the statement is coerced into a :func:`sqlalchemy.sql.expression.text` construct. This construct considers symbols with colons, e.g. ``:foo`` to be bound parameters. To avoid this, ensure that colon symbols are escaped, e.g. ``\:foo``. :param execution_options: Optional dictionary of execution options, will be passed to :meth:`sqlalchemy.engine.Connection.execution_options`. """ op = cls(sqltext, execution_options=execution_options) return operations.invoke(op) @classmethod def batch_execute( cls, operations: Operations, sqltext: Union[str, TextClause, Update], , execution_options: Optional[dict[str, Any]] = None, ) -> None: """Execute the given SQL using the current migration context. .. seealso:: :meth:`.Operations.execute` """ return cls.execute( operations, sqltext, execution_options=execution_options ) class OpContainer(MigrateOperation): """Represent a sequence of operations operation.""" def __init__(self, ops: Sequence[MigrateOperation] = ()) -> None: self.ops = list(ops) def is_empty(self) -> bool: return not self.ops def as_diffs(self) -> Any: return list(OpContainer._ops_as_diffs(self)) @classmethod def _ops_as_diffs( cls, migrations: OpContainer ) -> Iterator[Tuple[Any, ...]]: for op in migrations.ops: if hasattr(op, "ops"): yield from cls._ops_as_diffs(cast("OpContainer", op)) else: yield op.to_diff_tuple() class ModifyTableOps(OpContainer): """Contains a sequence of operations that all apply to a single Table.""" def __init__( self, table_name: str, ops: Sequence[MigrateOperation], , schema: Optional[str] = None, ) -> None: super().__init__(ops) self.table_name = table_name self.schema = schema def reverse(self) -> ModifyTableOps: return ModifyTableOps( self.table_name, ops=list(reversed([op.reverse() for op in self.ops])), schema=self.schema, ) class UpgradeOps(OpContainer): """contains a sequence of operations that would apply to the 'upgrade' stream of a script. .. seealso:: :ref:`customizing_revision` """ def __init__( self, ops: Sequence[MigrateOperation] = (), upgrade_token: str = "upgrades", ) -> None: super().__init__(ops=ops) self.upgrade_token = upgrade_token def reverse_into(self, downgrade_ops: DowngradeOps) -> DowngradeOps: downgrade_ops.ops[:] = list( # type:ignore[index] reversed([op.reverse() for op in self.ops]) ) return downgrade_ops def reverse(self) -> DowngradeOps: return self.reverse_into(DowngradeOps(ops=[])) class DowngradeOps(OpContainer): """contains a sequence of operations that would apply to the 'downgrade' stream of a script. .. seealso:: :ref:`customizing_revision` """ def __init__( self, ops: Sequence[MigrateOperation] = (), downgrade_token: str = "downgrades", ) -> None: super().__init__(ops=ops) self.downgrade_token = downgrade_token def reverse(self): return UpgradeOps( ops=list(reversed([op.reverse() for op in self.ops])) ) class MigrationScript(MigrateOperation): """represents a migration script. E.g. when autogenerate encounters this object, this corresponds to the production of an actual script file. A normal :class:`.MigrationScript` object would contain a single :class:`.UpgradeOps` and a single :class:`.DowngradeOps` directive. These are accessible via the ``.upgrade_ops`` and ``.downgrade_ops`` attributes. In the case of an autogenerate operation that runs multiple times, such as the multiple database example in the "multidb" template, the ``.upgrade_ops`` and ``.downgrade_ops`` attributes are disabled, and instead these objects should be accessed via the ``.upgrade_ops_list`` and ``.downgrade_ops_list`` list-based attributes. These latter attributes are always available at the very least as single-element lists. .. seealso:: :ref:`customizing_revision` """ _needs_render: Optional[bool] def __init__( self, rev_id: Optional[str], upgrade_ops: UpgradeOps, downgrade_ops: DowngradeOps, *, message: Optional[str] = None, imports: Set[str] = set(), head: Optional[str] = None, splice: Optional[bool] = None, branch_label: Optional[str] = None, version_path: Optional[str] = None, depends_on: Optional[Union[str, Sequence[str]]] = None, ) -> None: self.rev_id = rev_id self.message = message self.imports = imports self.head = head self.splice = splice self.branch_label = branch_label self.version_path = version_path self.depends_on = depends_on self.upgrade_ops = upgrade_ops self.downgrade_ops = downgrade_ops @property def upgrade_ops(self): """An instance of :class:`.UpgradeOps`. .. seealso:: :attr:`.MigrationScript.upgrade_ops_list` """ if len(self._upgrade_ops) > 1: raise ValueError( "This MigrationScript instance has a multiple-entry " "list for UpgradeOps; please use the " "upgrade_ops_list attribute." ) elif not self._upgrade_ops: return None else: return self._upgrade_ops[0] @upgrade_ops.setter def upgrade_ops(self, upgrade_ops): self._upgrade_ops = util.to_list(upgrade_ops) for elem in self._upgrade_ops: assert isinstance(elem, UpgradeOps) @property def downgrade_ops(self): """An instance of :class:`.DowngradeOps`. .. seealso:: :attr:`.MigrationScript.downgrade_ops_list` """ if len(self._downgrade_ops) > 1: raise ValueError( "This MigrationScript instance has a multiple-entry " "list for DowngradeOps; please use the " "downgrade_ops_list attribute." ) elif not self._downgrade_ops: return None else: return self._downgrade_ops[0] @downgrade_ops.setter def downgrade_ops(self, downgrade_ops): self._downgrade_ops = util.to_list(downgrade_ops) for elem in self._downgrade_ops: assert isinstance(elem, DowngradeOps) @property def upgrade_ops_list(self) -> List[UpgradeOps]: """A list of :class:`.UpgradeOps` instances. This is used in place of the :attr:`.MigrationScript.upgrade_ops` attribute when dealing with a revision operation that does multiple autogenerate passes. """ return self._upgrade_ops @property def downgrade_ops_list(self) -> List[DowngradeOps]: """A list of :class:`.DowngradeOps` instances. This is used in place of the :attr:`.MigrationScript.downgrade_ops` attribute when dealing with a revision operation that does multiple autogenerate passes. """ return self._downgrade_ops	90.91 KB	2026-01-20 12:58
📄 schemaobj.py from __future__ import annotations from typing import Any from typing import Dict from typing import List from typing import Optional from typing import Sequence from typing import Tuple from typing import TYPE_CHECKING from typing import Union from sqlalchemy import schema as sa_schema from sqlalchemy.sql.schema import Column from sqlalchemy.sql.schema import Constraint from sqlalchemy.sql.schema import Index from sqlalchemy.types import Integer from sqlalchemy.types import NULLTYPE from .. import util from ..util import sqla_compat if TYPE_CHECKING: from sqlalchemy.sql.elements import ColumnElement from sqlalchemy.sql.elements import TextClause from sqlalchemy.sql.schema import CheckConstraint from sqlalchemy.sql.schema import ForeignKey from sqlalchemy.sql.schema import ForeignKeyConstraint from sqlalchemy.sql.schema import MetaData from sqlalchemy.sql.schema import PrimaryKeyConstraint from sqlalchemy.sql.schema import Table from sqlalchemy.sql.schema import UniqueConstraint from sqlalchemy.sql.type_api import TypeEngine from ..runtime.migration import MigrationContext class SchemaObjects: def __init__( self, migration_context: Optional[MigrationContext] = None ) -> None: self.migration_context = migration_context def primary_key_constraint( self, name: Optional[sqla_compat._ConstraintNameDefined], table_name: str, cols: Sequence[str], schema: Optional[str] = None, *dialect_kw, ) -> PrimaryKeyConstraint: m = self.metadata() columns = [sa_schema.Column(n, NULLTYPE) for n in cols] t = sa_schema.Table(table_name, m, columns, schema=schema) # SQLAlchemy primary key constraint name arg is wrongly typed on # the SQLAlchemy side through 2.0.5 at least p = sa_schema.PrimaryKeyConstraint( [t.c[n] for n in cols], name=name, dialect_kw # type: ignore ) return p def foreign_key_constraint( self, name: Optional[sqla_compat._ConstraintNameDefined], source: str, referent: str, local_cols: List[str], remote_cols: List[str], onupdate: Optional[str] = None, ondelete: Optional[str] = None, deferrable: Optional[bool] = None, source_schema: Optional[str] = None, referent_schema: Optional[str] = None, initially: Optional[str] = None, match: Optional[str] = None, dialect_kw, ) -> ForeignKeyConstraint: m = self.metadata() if source == referent and source_schema == referent_schema: t1_cols = local_cols + remote_cols else: t1_cols = local_cols sa_schema.Table( referent, m, [sa_schema.Column(n, NULLTYPE) for n in remote_cols], schema=referent_schema, ) t1 = sa_schema.Table( source, m, [ sa_schema.Column(n, NULLTYPE) for n in util.unique_list(t1_cols) ], schema=source_schema, ) tname = ( "%s.%s" % (referent_schema, referent) if referent_schema else referent ) dialect_kw["match"] = match f = sa_schema.ForeignKeyConstraint( local_cols, ["%s.%s" % (tname, n) for n in remote_cols], name=name, onupdate=onupdate, ondelete=ondelete, deferrable=deferrable, initially=initially, dialect_kw, ) t1.append_constraint(f) return f def unique_constraint( self, name: Optional[sqla_compat._ConstraintNameDefined], source: str, local_cols: Sequence[str], schema: Optional[str] = None, kw, ) -> UniqueConstraint: t = sa_schema.Table( source, self.metadata(), [sa_schema.Column(n, NULLTYPE) for n in local_cols], schema=schema, ) kw["name"] = name uq = sa_schema.UniqueConstraint([t.c[n] for n in local_cols], kw) # TODO: need event tests to ensure the event # is fired off here t.append_constraint(uq) return uq def check_constraint( self, name: Optional[sqla_compat._ConstraintNameDefined], source: str, condition: Union[str, TextClause, ColumnElement[Any]], schema: Optional[str] = None, kw, ) -> Union[CheckConstraint]: t = sa_schema.Table( source, self.metadata(), sa_schema.Column("x", Integer), schema=schema, ) ck = sa_schema.CheckConstraint(condition, name=name, kw) t.append_constraint(ck) return ck def generic_constraint( self, name: Optional[sqla_compat._ConstraintNameDefined], table_name: str, type_: Optional[str], schema: Optional[str] = None, kw, ) -> Any: t = self.table(table_name, schema=schema) types: Dict[Optional[str], Any] = { "foreignkey": lambda name: sa_schema.ForeignKeyConstraint( [], [], name=name ), "primary": sa_schema.PrimaryKeyConstraint, "unique": sa_schema.UniqueConstraint, "check": lambda name: sa_schema.CheckConstraint("", name=name), None: sa_schema.Constraint, } try: const = types[type_] except KeyError as ke: raise TypeError( "'type' can be one of %s" % ", ".join(sorted(repr(x) for x in types)) ) from ke else: const = const(name=name) t.append_constraint(const) return const def metadata(self) -> MetaData: kw = {} if ( self.migration_context is not None and "target_metadata" in self.migration_context.opts ): mt = self.migration_context.opts["target_metadata"] if hasattr(mt, "naming_convention"): kw["naming_convention"] = mt.naming_convention return sa_schema.MetaData(kw) def table(self, name: str, columns, *kw) -> Table: m = self.metadata() cols = [ sqla_compat._copy(c) if c.table is not None else c for c in columns if isinstance(c, Column) ] # these flags have already added their UniqueConstraint / # Index objects to the table, so flip them off here. # SQLAlchemy tometadata() avoids this instead by preserving the # flags and skipping the constraints that have _type_bound on them, # but for a migration we'd rather list out the constraints # explicitly. _constraints_included = kw.pop("_constraints_included", False) if _constraints_included: for c in cols: c.unique = c.index = False t = sa_schema.Table(name, m, cols, kw) constraints = [ sqla_compat._copy(elem, target_table=t) if getattr(elem, "parent", None) is not t and getattr(elem, "parent", None) is not None else elem for elem in columns if isinstance(elem, (Constraint, Index)) ] for const in constraints: t.append_constraint(const) for f in t.foreign_keys: self._ensure_table_for_fk(m, f) return t def column(self, name: str, type_: TypeEngine, kw) -> Column: return sa_schema.Column(name, type_, kw) def index( self, name: Optional[str], tablename: Optional[str], columns: Sequence[Union[str, TextClause, ColumnElement[Any]]], schema: Optional[str] = None, kw, ) -> Index: t = sa_schema.Table( tablename or "no_table", self.metadata(), schema=schema, ) kw["_table"] = t idx = sa_schema.Index( name, [util.sqla_compat._textual_index_column(t, n) for n in columns], *kw, ) return idx def _parse_table_key(self, table_key: str) -> Tuple[Optional[str], str]: if "." in table_key: tokens = table_key.split(".") sname: Optional[str] = ".".join(tokens[0:-1]) tname = tokens[-1] else: tname = table_key sname = None return (sname, tname) def _ensure_table_for_fk(self, metadata: MetaData, fk: ForeignKey) -> None: """create a placeholder Table object for the referent of a ForeignKey. """ if isinstance(fk._colspec, str): # type:ignore[attr-defined] table_key, cname = fk._colspec.rsplit( # type:ignore[attr-defined] ".", 1 ) sname, tname = self._parse_table_key(table_key) if table_key not in metadata.tables: rel_t = sa_schema.Table(tname, metadata, schema=sname) else: rel_t = metadata.tables[table_key] if cname not in rel_t.c: rel_t.append_column(sa_schema.Column(cname, NULLTYPE))	9.17 KB	2026-01-20 12:58
📄 toimpl.py from typing import TYPE_CHECKING from sqlalchemy import schema as sa_schema from . import ops from .base import Operations from ..util.sqla_compat import _copy if TYPE_CHECKING: from sqlalchemy.sql.schema import Table @Operations.implementation_for(ops.AlterColumnOp) def alter_column( operations: "Operations", operation: "ops.AlterColumnOp" ) -> None: compiler = operations.impl.dialect.statement_compiler( operations.impl.dialect, None ) existing_type = operation.existing_type existing_nullable = operation.existing_nullable existing_server_default = operation.existing_server_default type_ = operation.modify_type column_name = operation.column_name table_name = operation.table_name schema = operation.schema server_default = operation.modify_server_default new_column_name = operation.modify_name nullable = operation.modify_nullable comment = operation.modify_comment existing_comment = operation.existing_comment def _count_constraint(constraint): return not isinstance(constraint, sa_schema.PrimaryKeyConstraint) and ( not constraint._create_rule or constraint._create_rule(compiler) ) if existing_type and type_: t = operations.schema_obj.table( table_name, sa_schema.Column(column_name, existing_type), schema=schema, ) for constraint in t.constraints: if _count_constraint(constraint): operations.impl.drop_constraint(constraint) operations.impl.alter_column( table_name, column_name, nullable=nullable, server_default=server_default, name=new_column_name, type_=type_, schema=schema, existing_type=existing_type, existing_server_default=existing_server_default, existing_nullable=existing_nullable, comment=comment, existing_comment=existing_comment, operation.kw ) if type_: t = operations.schema_obj.table( table_name, operations.schema_obj.column(column_name, type_), schema=schema, ) for constraint in t.constraints: if _count_constraint(constraint): operations.impl.add_constraint(constraint) @Operations.implementation_for(ops.DropTableOp) def drop_table(operations: "Operations", operation: "ops.DropTableOp") -> None: operations.impl.drop_table( operation.to_table(operations.migration_context) ) @Operations.implementation_for(ops.DropColumnOp) def drop_column( operations: "Operations", operation: "ops.DropColumnOp" ) -> None: column = operation.to_column(operations.migration_context) operations.impl.drop_column( operation.table_name, column, schema=operation.schema, operation.kw ) @Operations.implementation_for(ops.CreateIndexOp) def create_index( operations: "Operations", operation: "ops.CreateIndexOp" ) -> None: idx = operation.to_index(operations.migration_context) operations.impl.create_index(idx) @Operations.implementation_for(ops.DropIndexOp) def drop_index(operations: "Operations", operation: "ops.DropIndexOp") -> None: operations.impl.drop_index( operation.to_index(operations.migration_context) ) @Operations.implementation_for(ops.CreateTableOp) def create_table( operations: "Operations", operation: "ops.CreateTableOp" ) -> "Table": table = operation.to_table(operations.migration_context) operations.impl.create_table(table) return table @Operations.implementation_for(ops.RenameTableOp) def rename_table( operations: "Operations", operation: "ops.RenameTableOp" ) -> None: operations.impl.rename_table( operation.table_name, operation.new_table_name, schema=operation.schema ) @Operations.implementation_for(ops.CreateTableCommentOp) def create_table_comment( operations: "Operations", operation: "ops.CreateTableCommentOp" ) -> None: table = operation.to_table(operations.migration_context) operations.impl.create_table_comment(table) @Operations.implementation_for(ops.DropTableCommentOp) def drop_table_comment( operations: "Operations", operation: "ops.DropTableCommentOp" ) -> None: table = operation.to_table(operations.migration_context) operations.impl.drop_table_comment(table) @Operations.implementation_for(ops.AddColumnOp) def add_column(operations: "Operations", operation: "ops.AddColumnOp") -> None: table_name = operation.table_name column = operation.column schema = operation.schema kw = operation.kw if column.table is not None: column = _copy(column) t = operations.schema_obj.table(table_name, column, schema=schema) operations.impl.add_column(table_name, column, schema=schema, **kw) for constraint in t.constraints: if not isinstance(constraint, sa_schema.PrimaryKeyConstraint): operations.impl.add_constraint(constraint) for index in t.indexes: operations.impl.create_index(index) with_comment = ( operations.impl.dialect.supports_comments and not operations.impl.dialect.inline_comments ) comment = column.comment if comment and with_comment: operations.impl.create_column_comment(column) @Operations.implementation_for(ops.AddConstraintOp) def create_constraint( operations: "Operations", operation: "ops.AddConstraintOp" ) -> None: operations.impl.add_constraint( operation.to_constraint(operations.migration_context) ) @Operations.implementation_for(ops.DropConstraintOp) def drop_constraint( operations: "Operations", operation: "ops.DropConstraintOp" ) -> None: operations.impl.drop_constraint( operations.schema_obj.generic_constraint( operation.constraint_name, operation.table_name, operation.constraint_type, schema=operation.schema, ) ) @Operations.implementation_for(ops.BulkInsertOp) def bulk_insert( operations: "Operations", operation: "ops.BulkInsertOp" ) -> None: operations.impl.bulk_insert( # type: ignore[union-attr] operation.table, operation.rows, multiinsert=operation.multiinsert ) @Operations.implementation_for(ops.ExecuteSQLOp) def execute_sql( operations: "Operations", operation: "ops.ExecuteSQLOp" ) -> None: operations.migration_context.impl.execute( operation.sqltext, execution_options=operation.execution_options )	6.39 KB	2026-01-20 12:58

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