Загрузить файлы в «venv/Lib/site-packages/sqlalchemy/sql»

venv/Lib/site-packages/sqlalchemy/sql/events.py

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+# sql/events.py
+# Copyright (C) 2005-2026 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: https://www.opensource.org/licenses/mit-license.php
+
+from __future__ import annotations
+
+from typing import Any
+from typing import TYPE_CHECKING
+
+from .base import SchemaEventTarget
+from .. import event
+
+if TYPE_CHECKING:
+    from .schema import Column
+    from .schema import Constraint
+    from .schema import SchemaItem
+    from .schema import Table
+    from ..engine.base import Connection
+    from ..engine.interfaces import ReflectedColumn
+    from ..engine.reflection import Inspector
+
+
+class DDLEvents(event.Events[SchemaEventTarget]):
+    """
+    Define event listeners for schema objects,
+    that is, :class:`.SchemaItem` and other :class:`.SchemaEventTarget`
+    subclasses, including :class:`_schema.MetaData`, :class:`_schema.Table`,
+    :class:`_schema.Column`, etc.
+
+    **Create / Drop Events**
+
+    Events emitted when CREATE and DROP commands are emitted to the database.
+    The event hooks in this category include :meth:`.DDLEvents.before_create`,
+    :meth:`.DDLEvents.after_create`, :meth:`.DDLEvents.before_drop`, and
+    :meth:`.DDLEvents.after_drop`.
+
+    These events are emitted when using schema-level methods such as
+    :meth:`.MetaData.create_all` and :meth:`.MetaData.drop_all`. Per-object
+    create/drop methods such as :meth:`.Table.create`, :meth:`.Table.drop`,
+    :meth:`.Index.create` are also included, as well as dialect-specific
+    methods such as :meth:`_postgresql.ENUM.create`.
+
+    .. versionadded:: 2.0 :class:`.DDLEvents` event hooks now take place
+       for non-table objects including constraints, indexes, and
+       dialect-specific schema types.
+
+    Event hooks may be attached directly to a :class:`_schema.Table` object or
+    to a :class:`_schema.MetaData` collection, as well as to any
+    :class:`.SchemaItem` class or object that can be individually created and
+    dropped using a distinct SQL command. Such classes include :class:`.Index`,
+    :class:`.Sequence`, and dialect-specific classes such as
+    :class:`_postgresql.ENUM`.
+
+    Example using the :meth:`.DDLEvents.after_create` event, where a custom
+    event hook will emit an ``ALTER TABLE`` command on the current connection,
+    after ``CREATE TABLE`` is emitted::
+
+        from sqlalchemy import create_engine
+        from sqlalchemy import event
+        from sqlalchemy import Table, Column, Metadata, Integer
+
+        m = MetaData()
+        some_table = Table("some_table", m, Column("data", Integer))
+
+
+        @event.listens_for(some_table, "after_create")
+        def after_create(target, connection, **kw):
+            connection.execute(
+                text("ALTER TABLE %s SET name=foo_%s" % (target.name, target.name))
+            )
+
+
+        some_engine = create_engine("postgresql://scott:tiger@host/test")
+
+        # will emit "CREATE TABLE some_table" as well as the above
+        # "ALTER TABLE" statement afterwards
+        m.create_all(some_engine)
+
+    Constraint objects such as :class:`.ForeignKeyConstraint`,
+    :class:`.UniqueConstraint`, :class:`.CheckConstraint` may also be
+    subscribed to these events, however they will **not** normally produce
+    events as these objects are usually rendered inline within an
+    enclosing ``CREATE TABLE`` statement and implicitly dropped from a
+    ``DROP TABLE`` statement.
+
+    For the :class:`.Index` construct, the event hook will be emitted
+    for ``CREATE INDEX``, however SQLAlchemy does not normally emit
+    ``DROP INDEX`` when dropping tables as this is again implicit within the
+    ``DROP TABLE`` statement.
+
+    .. versionadded:: 2.0 Support for :class:`.SchemaItem` objects
+       for create/drop events was expanded from its previous support for
+       :class:`.MetaData` and :class:`.Table` to also include
+       :class:`.Constraint` and all subclasses, :class:`.Index`,
+       :class:`.Sequence` and some type-related constructs such as
+       :class:`_postgresql.ENUM`.
+
+    .. note:: These event hooks are only emitted within the scope of
+       SQLAlchemy's create/drop methods; they are not necessarily supported
+       by tools such as `alembic <https://alembic.sqlalchemy.org>`_.
+
+
+    **Attachment Events**
+
+    Attachment events are provided to customize
+    behavior whenever a child schema element is associated
+    with a parent, such as when a :class:`_schema.Column` is associated
+    with its :class:`_schema.Table`, when a
+    :class:`_schema.ForeignKeyConstraint`
+    is associated with a :class:`_schema.Table`, etc.  These events include
+    :meth:`.DDLEvents.before_parent_attach` and
+    :meth:`.DDLEvents.after_parent_attach`.
+
+    **Reflection Events**
+
+    The :meth:`.DDLEvents.column_reflect` event is used to intercept
+    and modify the in-Python definition of database columns when
+    :term:`reflection` of database tables proceeds.
+
+    **Use with Generic DDL**
+
+    DDL events integrate closely with the
+    :class:`.DDL` class and the :class:`.ExecutableDDLElement` hierarchy
+    of DDL clause constructs, which are themselves appropriate
+    as listener callables::
+
+        from sqlalchemy import DDL
+
+        event.listen(
+            some_table,
+            "after_create",
+            DDL("ALTER TABLE %(table)s SET name=foo_%(table)s"),
+        )
+
+    **Event Propagation to MetaData Copies**
+
+    For all :class:`.DDLEvent` events, the ``propagate=True`` keyword argument
+    will ensure that a given event handler is propagated to copies of the
+    object, which are made when using the :meth:`_schema.Table.to_metadata`
+    method::
+
+        from sqlalchemy import DDL
+
+        metadata = MetaData()
+        some_table = Table("some_table", metadata, Column("data", Integer))
+
+        event.listen(
+            some_table,
+            "after_create",
+            DDL("ALTER TABLE %(table)s SET name=foo_%(table)s"),
+            propagate=True,
+        )
+
+        new_metadata = MetaData()
+        new_table = some_table.to_metadata(new_metadata)
+
+    The above :class:`.DDL` object will be associated with the
+    :meth:`.DDLEvents.after_create` event for both the ``some_table`` and
+    the ``new_table`` :class:`.Table` objects.
+
+    .. seealso::
+
+        :ref:`event_toplevel`
+
+        :class:`.ExecutableDDLElement`
+
+        :class:`.DDL`
+
+        :ref:`schema_ddl_sequences`
+
+    """  # noqa: E501
+
+    _target_class_doc = "SomeSchemaClassOrObject"
+    _dispatch_target = SchemaEventTarget
+
+    def before_create(
+        self, target: SchemaEventTarget, connection: Connection, **kw: Any
+    ) -> None:
+        r"""Called before CREATE statements are emitted.
+
+        :param target: the :class:`.SchemaObject`, such as a
+         :class:`_schema.MetaData` or :class:`_schema.Table`
+         but also including all create/drop objects such as
+         :class:`.Index`, :class:`.Sequence`, etc.,
+         object which is the target of the event.
+
+         .. versionadded:: 2.0 Support for all :class:`.SchemaItem` objects
+            was added.
+
+        :param connection: the :class:`_engine.Connection` where the
+         CREATE statement or statements will be emitted.
+        :param \**kw: additional keyword arguments relevant
+         to the event.  The contents of this dictionary
+         may vary across releases, and include the
+         list of tables being generated for a metadata-level
+         event, the checkfirst flag, and other
+         elements used by internal events.
+
+        :func:`.event.listen` accepts the ``propagate=True``
+        modifier for this event; when True, the listener function will
+        be established for any copies made of the target object,
+        i.e. those copies that are generated when
+        :meth:`_schema.Table.to_metadata` is used.
+
+        :func:`.event.listen` accepts the ``insert=True``
+        modifier for this event; when True, the listener function will
+        be prepended to the internal list of events upon discovery, and execute
+        before registered listener functions that do not pass this argument.
+
+        """
+
+    def after_create(
+        self, target: SchemaEventTarget, connection: Connection, **kw: Any
+    ) -> None:
+        r"""Called after CREATE statements are emitted.
+
+        :param target: the :class:`.SchemaObject`, such as a
+         :class:`_schema.MetaData` or :class:`_schema.Table`
+         but also including all create/drop objects such as
+         :class:`.Index`, :class:`.Sequence`, etc.,
+         object which is the target of the event.
+
+         .. versionadded:: 2.0 Support for all :class:`.SchemaItem` objects
+            was added.
+
+        :param connection: the :class:`_engine.Connection` where the
+         CREATE statement or statements have been emitted.
+        :param \**kw: additional keyword arguments relevant
+         to the event.  The contents of this dictionary
+         may vary across releases, and include the
+         list of tables being generated for a metadata-level
+         event, the checkfirst flag, and other
+         elements used by internal events.
+
+        :func:`.event.listen` also accepts the ``propagate=True``
+        modifier for this event; when True, the listener function will
+        be established for any copies made of the target object,
+        i.e. those copies that are generated when
+        :meth:`_schema.Table.to_metadata` is used.
+
+        """
+
+    def before_drop(
+        self, target: SchemaEventTarget, connection: Connection, **kw: Any
+    ) -> None:
+        r"""Called before DROP statements are emitted.
+
+        :param target: the :class:`.SchemaObject`, such as a
+         :class:`_schema.MetaData` or :class:`_schema.Table`
+         but also including all create/drop objects such as
+         :class:`.Index`, :class:`.Sequence`, etc.,
+         object which is the target of the event.
+
+         .. versionadded:: 2.0 Support for all :class:`.SchemaItem` objects
+            was added.
+
+        :param connection: the :class:`_engine.Connection` where the
+         DROP statement or statements will be emitted.
+        :param \**kw: additional keyword arguments relevant
+         to the event.  The contents of this dictionary
+         may vary across releases, and include the
+         list of tables being generated for a metadata-level
+         event, the checkfirst flag, and other
+         elements used by internal events.
+
+        :func:`.event.listen` also accepts the ``propagate=True``
+        modifier for this event; when True, the listener function will
+        be established for any copies made of the target object,
+        i.e. those copies that are generated when
+        :meth:`_schema.Table.to_metadata` is used.
+
+        """
+
+    def after_drop(
+        self, target: SchemaEventTarget, connection: Connection, **kw: Any
+    ) -> None:
+        r"""Called after DROP statements are emitted.
+
+        :param target: the :class:`.SchemaObject`, such as a
+         :class:`_schema.MetaData` or :class:`_schema.Table`
+         but also including all create/drop objects such as
+         :class:`.Index`, :class:`.Sequence`, etc.,
+         object which is the target of the event.
+
+         .. versionadded:: 2.0 Support for all :class:`.SchemaItem` objects
+            was added.
+
+        :param connection: the :class:`_engine.Connection` where the
+         DROP statement or statements have been emitted.
+        :param \**kw: additional keyword arguments relevant
+         to the event.  The contents of this dictionary
+         may vary across releases, and include the
+         list of tables being generated for a metadata-level
+         event, the checkfirst flag, and other
+         elements used by internal events.
+
+        :func:`.event.listen` also accepts the ``propagate=True``
+        modifier for this event; when True, the listener function will
+        be established for any copies made of the target object,
+        i.e. those copies that are generated when
+        :meth:`_schema.Table.to_metadata` is used.
+
+        """
+
+    def before_parent_attach(
+        self, target: SchemaEventTarget, parent: SchemaItem
+    ) -> None:
+        """Called before a :class:`.SchemaItem` is associated with
+        a parent :class:`.SchemaItem`.
+
+        :param target: the target object
+        :param parent: the parent to which the target is being attached.
+
+        :func:`.event.listen` also accepts the ``propagate=True``
+        modifier for this event; when True, the listener function will
+        be established for any copies made of the target object,
+        i.e. those copies that are generated when
+        :meth:`_schema.Table.to_metadata` is used.
+
+        """
+
+    def after_parent_attach(
+        self, target: SchemaEventTarget, parent: SchemaItem
+    ) -> None:
+        """Called after a :class:`.SchemaItem` is associated with
+        a parent :class:`.SchemaItem`.
+
+        :param target: the target object
+        :param parent: the parent to which the target is being attached.
+
+        :func:`.event.listen` also accepts the ``propagate=True``
+        modifier for this event; when True, the listener function will
+        be established for any copies made of the target object,
+        i.e. those copies that are generated when
+        :meth:`_schema.Table.to_metadata` is used.
+
+        """
+
+    def _sa_event_column_added_to_pk_constraint(
+        self, const: Constraint, col: Column[Any]
+    ) -> None:
+        """internal event hook used for primary key naming convention
+        updates.
+
+        """
+
+    def column_reflect(
+        self, inspector: Inspector, table: Table, column_info: ReflectedColumn
+    ) -> None:
+        """Called for each unit of 'column info' retrieved when
+        a :class:`_schema.Table` is being reflected.
+
+        This event is most easily used by applying it to a specific
+        :class:`_schema.MetaData` instance, where it will take effect for
+        all :class:`_schema.Table` objects within that
+        :class:`_schema.MetaData` that undergo reflection::
+
+            metadata = MetaData()
+
+
+            @event.listens_for(metadata, "column_reflect")
+            def receive_column_reflect(inspector, table, column_info):
+                # receives for all Table objects that are reflected
+                # under this MetaData
+                ...
+
+
+            # will use the above event hook
+            my_table = Table("my_table", metadata, autoload_with=some_engine)
+
+        .. versionadded:: 1.4.0b2 The :meth:`_events.DDLEvents.column_reflect`
+           hook may now be applied to a :class:`_schema.MetaData` object as
+           well as the :class:`_schema.MetaData` class itself where it will
+           take place for all :class:`_schema.Table` objects associated with
+           the targeted :class:`_schema.MetaData`.
+
+        It may also be applied to the :class:`_schema.Table` class across
+        the board::
+
+            from sqlalchemy import Table
+
+
+            @event.listens_for(Table, "column_reflect")
+            def receive_column_reflect(inspector, table, column_info):
+                # receives for all Table objects that are reflected
+                ...
+
+        It can also be applied to a specific :class:`_schema.Table` at the
+        point that one is being reflected using the
+        :paramref:`_schema.Table.listeners` parameter::
+
+            t1 = Table(
+                "my_table",
+                autoload_with=some_engine,
+                listeners=[("column_reflect", receive_column_reflect)],
+            )
+
+        The dictionary of column information as returned by the
+        dialect is passed, and can be modified.  The dictionary
+        is that returned in each element of the list returned
+        by :meth:`.reflection.Inspector.get_columns`:
+
+            * ``name`` - the column's name, is applied to the
+              :paramref:`_schema.Column.name` parameter
+
+            * ``type`` - the type of this column, which should be an instance
+              of :class:`~sqlalchemy.types.TypeEngine`, is applied to the
+              :paramref:`_schema.Column.type` parameter
+
+            * ``nullable`` - boolean flag if the column is NULL or NOT NULL,
+              is applied to the :paramref:`_schema.Column.nullable` parameter
+
+            * ``default`` - the column's server default value.  This is
+              normally specified as a plain string SQL expression, however the
+              event can pass a :class:`.FetchedValue`, :class:`.DefaultClause`,
+              or :func:`_expression.text` object as well.  Is applied to the
+              :paramref:`_schema.Column.server_default` parameter
+
+        The event is called before any action is taken against
+        this dictionary, and the contents can be modified; the following
+        additional keys may be added to the dictionary to further modify
+        how the :class:`_schema.Column` is constructed:
+
+
+            * ``key`` - the string key that will be used to access this
+              :class:`_schema.Column` in the ``.c`` collection; will be applied
+              to the :paramref:`_schema.Column.key` parameter. Is also used
+              for ORM mapping.  See the section
+              :ref:`mapper_automated_reflection_schemes` for an example.
+
+            * ``quote`` - force or un-force quoting on the column name;
+              is applied to the :paramref:`_schema.Column.quote` parameter.
+
+            * ``info`` - a dictionary of arbitrary data to follow along with
+              the :class:`_schema.Column`, is applied to the
+              :paramref:`_schema.Column.info` parameter.
+
+        :func:`.event.listen` also accepts the ``propagate=True``
+        modifier for this event; when True, the listener function will
+        be established for any copies made of the target object,
+        i.e. those copies that are generated when
+        :meth:`_schema.Table.to_metadata` is used.
+
+        .. seealso::
+
+            :ref:`mapper_automated_reflection_schemes` -
+            in the ORM mapping documentation
+
+            :ref:`automap_intercepting_columns` -
+            in the :ref:`automap_toplevel` documentation
+
+            :ref:`metadata_reflection_dbagnostic_types` - in
+            the :ref:`metadata_reflection_toplevel` documentation
+
+        """

venv/Lib/site-packages/sqlalchemy/sql/expression.py

@@ -0,0 +1,158 @@
+# sql/expression.py
+# Copyright (C) 2005-2026 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: https://www.opensource.org/licenses/mit-license.php
+
+"""Defines the public namespace for SQL expression constructs."""
+
+from __future__ import annotations
+
+from ._dml_constructors import delete as delete
+from ._dml_constructors import insert as insert
+from ._dml_constructors import update as update
+from ._elements_constructors import all_ as all_
+from ._elements_constructors import and_ as and_
+from ._elements_constructors import any_ as any_
+from ._elements_constructors import asc as asc
+from ._elements_constructors import between as between
+from ._elements_constructors import bindparam as bindparam
+from ._elements_constructors import bitwise_not as bitwise_not
+from ._elements_constructors import case as case
+from ._elements_constructors import cast as cast
+from ._elements_constructors import collate as collate
+from ._elements_constructors import column as column
+from ._elements_constructors import desc as desc
+from ._elements_constructors import distinct as distinct
+from ._elements_constructors import extract as extract
+from ._elements_constructors import false as false
+from ._elements_constructors import funcfilter as funcfilter
+from ._elements_constructors import label as label
+from ._elements_constructors import not_ as not_
+from ._elements_constructors import null as null
+from ._elements_constructors import nulls_first as nulls_first
+from ._elements_constructors import nulls_last as nulls_last
+from ._elements_constructors import or_ as or_
+from ._elements_constructors import outparam as outparam
+from ._elements_constructors import over as over
+from ._elements_constructors import text as text
+from ._elements_constructors import true as true
+from ._elements_constructors import try_cast as try_cast
+from ._elements_constructors import tuple_ as tuple_
+from ._elements_constructors import type_coerce as type_coerce
+from ._elements_constructors import within_group as within_group
+from ._selectable_constructors import alias as alias
+from ._selectable_constructors import cte as cte
+from ._selectable_constructors import except_ as except_
+from ._selectable_constructors import except_all as except_all
+from ._selectable_constructors import exists as exists
+from ._selectable_constructors import intersect as intersect
+from ._selectable_constructors import intersect_all as intersect_all
+from ._selectable_constructors import join as join
+from ._selectable_constructors import lateral as lateral
+from ._selectable_constructors import outerjoin as outerjoin
+from ._selectable_constructors import select as select
+from ._selectable_constructors import table as table
+from ._selectable_constructors import tablesample as tablesample
+from ._selectable_constructors import union as union
+from ._selectable_constructors import union_all as union_all
+from ._selectable_constructors import values as values
+from ._typing import ColumnExpressionArgument as ColumnExpressionArgument
+from .base import _from_objects as _from_objects
+from .base import _select_iterables as _select_iterables
+from .base import ColumnCollection as ColumnCollection
+from .base import Executable as Executable
+from .cache_key import CacheKey as CacheKey
+from .dml import Delete as Delete
+from .dml import Insert as Insert
+from .dml import Update as Update
+from .dml import UpdateBase as UpdateBase
+from .dml import ValuesBase as ValuesBase
+from .elements import _truncated_label as _truncated_label
+from .elements import BinaryExpression as BinaryExpression
+from .elements import BindParameter as BindParameter
+from .elements import BooleanClauseList as BooleanClauseList
+from .elements import Case as Case
+from .elements import Cast as Cast
+from .elements import ClauseElement as ClauseElement
+from .elements import ClauseList as ClauseList
+from .elements import CollectionAggregate as CollectionAggregate
+from .elements import ColumnClause as ColumnClause
+from .elements import ColumnElement as ColumnElement
+from .elements import ExpressionClauseList as ExpressionClauseList
+from .elements import Extract as Extract
+from .elements import False_ as False_
+from .elements import FunctionFilter as FunctionFilter
+from .elements import Grouping as Grouping
+from .elements import Label as Label
+from .elements import literal as literal
+from .elements import literal_column as literal_column
+from .elements import Null as Null
+from .elements import Over as Over
+from .elements import quoted_name as quoted_name
+from .elements import ReleaseSavepointClause as ReleaseSavepointClause
+from .elements import RollbackToSavepointClause as RollbackToSavepointClause
+from .elements import SavepointClause as SavepointClause
+from .elements import SQLColumnExpression as SQLColumnExpression
+from .elements import TextClause as TextClause
+from .elements import True_ as True_
+from .elements import TryCast as TryCast
+from .elements import Tuple as Tuple
+from .elements import TypeClause as TypeClause
+from .elements import TypeCoerce as TypeCoerce
+from .elements import UnaryExpression as UnaryExpression
+from .elements import WithinGroup as WithinGroup
+from .functions import func as func
+from .functions import Function as Function
+from .functions import FunctionElement as FunctionElement
+from .functions import modifier as modifier
+from .lambdas import lambda_stmt as lambda_stmt
+from .lambdas import LambdaElement as LambdaElement
+from .lambdas import StatementLambdaElement as StatementLambdaElement
+from .operators import ColumnOperators as ColumnOperators
+from .operators import custom_op as custom_op
+from .operators import Operators as Operators
+from .selectable import Alias as Alias
+from .selectable import AliasedReturnsRows as AliasedReturnsRows
+from .selectable import CompoundSelect as CompoundSelect
+from .selectable import CTE as CTE
+from .selectable import Exists as Exists
+from .selectable import FromClause as FromClause
+from .selectable import FromGrouping as FromGrouping
+from .selectable import GenerativeSelect as GenerativeSelect
+from .selectable import HasCTE as HasCTE
+from .selectable import HasPrefixes as HasPrefixes
+from .selectable import HasSuffixes as HasSuffixes
+from .selectable import Join as Join
+from .selectable import LABEL_STYLE_DEFAULT as LABEL_STYLE_DEFAULT
+from .selectable import (
+    LABEL_STYLE_DISAMBIGUATE_ONLY as LABEL_STYLE_DISAMBIGUATE_ONLY,
+)
+from .selectable import LABEL_STYLE_NONE as LABEL_STYLE_NONE
+from .selectable import (
+    LABEL_STYLE_TABLENAME_PLUS_COL as LABEL_STYLE_TABLENAME_PLUS_COL,
+)
+from .selectable import Lateral as Lateral
+from .selectable import ReturnsRows as ReturnsRows
+from .selectable import ScalarSelect as ScalarSelect
+from .selectable import ScalarValues as ScalarValues
+from .selectable import Select as Select
+from .selectable import Selectable as Selectable
+from .selectable import SelectBase as SelectBase
+from .selectable import SelectLabelStyle as SelectLabelStyle
+from .selectable import Subquery as Subquery
+from .selectable import TableClause as TableClause
+from .selectable import TableSample as TableSample
+from .selectable import TableValuedAlias as TableValuedAlias
+from .selectable import TextAsFrom as TextAsFrom
+from .selectable import TextualSelect as TextualSelect
+from .selectable import Values as Values
+from .visitors import Visitable as Visitable
+
+nullsfirst = nulls_first
+"""Synonym for the :func:`.nulls_first` function."""
+
+
+nullslast = nulls_last
+"""Synonym for the :func:`.nulls_last` function."""