Update 2025-04-13_16:25:39
This commit is contained in:
root
@ -0,0 +1,339 @@
|
||||
# dialects/postgresql/dml.py
|
||||
# Copyright (C) 2005-2025 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 List
|
||||
from typing import Optional
|
||||
from typing import Tuple
|
||||
from typing import Union
|
||||
|
||||
from . import ext
|
||||
from .._typing import _OnConflictConstraintT
|
||||
from .._typing import _OnConflictIndexElementsT
|
||||
from .._typing import _OnConflictIndexWhereT
|
||||
from .._typing import _OnConflictSetT
|
||||
from .._typing import _OnConflictWhereT
|
||||
from ... import util
|
||||
from ...sql import coercions
|
||||
from ...sql import roles
|
||||
from ...sql import schema
|
||||
from ...sql._typing import _DMLTableArgument
|
||||
from ...sql.base import _exclusive_against
|
||||
from ...sql.base import _generative
|
||||
from ...sql.base import ColumnCollection
|
||||
from ...sql.base import ReadOnlyColumnCollection
|
||||
from ...sql.dml import Insert as StandardInsert
|
||||
from ...sql.elements import ClauseElement
|
||||
from ...sql.elements import ColumnElement
|
||||
from ...sql.elements import KeyedColumnElement
|
||||
from ...sql.elements import TextClause
|
||||
from ...sql.expression import alias
|
||||
from ...util.typing import Self
|
||||
|
||||
|
||||
__all__ = ("Insert", "insert")
|
||||
|
||||
|
||||
def insert(table: _DMLTableArgument) -> Insert:
|
||||
"""Construct a PostgreSQL-specific variant :class:`_postgresql.Insert`
|
||||
construct.
|
||||
|
||||
.. container:: inherited_member
|
||||
|
||||
The :func:`sqlalchemy.dialects.postgresql.insert` function creates
|
||||
a :class:`sqlalchemy.dialects.postgresql.Insert`. This class is based
|
||||
on the dialect-agnostic :class:`_sql.Insert` construct which may
|
||||
be constructed using the :func:`_sql.insert` function in
|
||||
SQLAlchemy Core.
|
||||
|
||||
The :class:`_postgresql.Insert` construct includes additional methods
|
||||
:meth:`_postgresql.Insert.on_conflict_do_update`,
|
||||
:meth:`_postgresql.Insert.on_conflict_do_nothing`.
|
||||
|
||||
"""
|
||||
return Insert(table)
|
||||
|
||||
|
||||
class Insert(StandardInsert):
|
||||
"""PostgreSQL-specific implementation of INSERT.
|
||||
|
||||
Adds methods for PG-specific syntaxes such as ON CONFLICT.
|
||||
|
||||
The :class:`_postgresql.Insert` object is created using the
|
||||
:func:`sqlalchemy.dialects.postgresql.insert` function.
|
||||
|
||||
"""
|
||||
|
||||
stringify_dialect = "postgresql"
|
||||
inherit_cache = False
|
||||
|
||||
@util.memoized_property
|
||||
def excluded(
|
||||
self,
|
||||
) -> ReadOnlyColumnCollection[str, KeyedColumnElement[Any]]:
|
||||
"""Provide the ``excluded`` namespace for an ON CONFLICT statement
|
||||
|
||||
PG's ON CONFLICT clause allows reference to the row that would
|
||||
be inserted, known as ``excluded``. This attribute provides
|
||||
all columns in this row to be referenceable.
|
||||
|
||||
.. tip:: The :attr:`_postgresql.Insert.excluded` attribute is an
|
||||
instance of :class:`_expression.ColumnCollection`, which provides
|
||||
an interface the same as that of the :attr:`_schema.Table.c`
|
||||
collection described at :ref:`metadata_tables_and_columns`.
|
||||
With this collection, ordinary names are accessible like attributes
|
||||
(e.g. ``stmt.excluded.some_column``), but special names and
|
||||
dictionary method names should be accessed using indexed access,
|
||||
such as ``stmt.excluded["column name"]`` or
|
||||
``stmt.excluded["values"]``. See the docstring for
|
||||
:class:`_expression.ColumnCollection` for further examples.
|
||||
|
||||
.. seealso::
|
||||
|
||||
:ref:`postgresql_insert_on_conflict` - example of how
|
||||
to use :attr:`_expression.Insert.excluded`
|
||||
|
||||
"""
|
||||
return alias(self.table, name="excluded").columns
|
||||
|
||||
_on_conflict_exclusive = _exclusive_against(
|
||||
"_post_values_clause",
|
||||
msgs={
|
||||
"_post_values_clause": "This Insert construct already has "
|
||||
"an ON CONFLICT clause established"
|
||||
},
|
||||
)
|
||||
|
||||
@_generative
|
||||
@_on_conflict_exclusive
|
||||
def on_conflict_do_update(
|
||||
self,
|
||||
constraint: _OnConflictConstraintT = None,
|
||||
index_elements: _OnConflictIndexElementsT = None,
|
||||
index_where: _OnConflictIndexWhereT = None,
|
||||
set_: _OnConflictSetT = None,
|
||||
where: _OnConflictWhereT = None,
|
||||
) -> Self:
|
||||
r"""
|
||||
Specifies a DO UPDATE SET action for ON CONFLICT clause.
|
||||
|
||||
Either the ``constraint`` or ``index_elements`` argument is
|
||||
required, but only one of these can be specified.
|
||||
|
||||
:param constraint:
|
||||
The name of a unique or exclusion constraint on the table,
|
||||
or the constraint object itself if it has a .name attribute.
|
||||
|
||||
:param index_elements:
|
||||
A sequence consisting of string column names, :class:`_schema.Column`
|
||||
objects, or other column expression objects that will be used
|
||||
to infer a target index.
|
||||
|
||||
:param index_where:
|
||||
Additional WHERE criterion that can be used to infer a
|
||||
conditional target index.
|
||||
|
||||
:param set\_:
|
||||
A dictionary or other mapping object
|
||||
where the keys are either names of columns in the target table,
|
||||
or :class:`_schema.Column` objects or other ORM-mapped columns
|
||||
matching that of the target table, and expressions or literals
|
||||
as values, specifying the ``SET`` actions to take.
|
||||
|
||||
.. versionadded:: 1.4 The
|
||||
:paramref:`_postgresql.Insert.on_conflict_do_update.set_`
|
||||
parameter supports :class:`_schema.Column` objects from the target
|
||||
:class:`_schema.Table` as keys.
|
||||
|
||||
.. warning:: This dictionary does **not** take into account
|
||||
Python-specified default UPDATE values or generation functions,
|
||||
e.g. those specified using :paramref:`_schema.Column.onupdate`.
|
||||
These values will not be exercised for an ON CONFLICT style of
|
||||
UPDATE, unless they are manually specified in the
|
||||
:paramref:`.Insert.on_conflict_do_update.set_` dictionary.
|
||||
|
||||
:param where:
|
||||
Optional argument. An expression object representing a ``WHERE``
|
||||
clause that restricts the rows affected by ``DO UPDATE SET``. Rows not
|
||||
meeting the ``WHERE`` condition will not be updated (effectively a
|
||||
``DO NOTHING`` for those rows).
|
||||
|
||||
|
||||
.. seealso::
|
||||
|
||||
:ref:`postgresql_insert_on_conflict`
|
||||
|
||||
"""
|
||||
self._post_values_clause = OnConflictDoUpdate(
|
||||
constraint, index_elements, index_where, set_, where
|
||||
)
|
||||
return self
|
||||
|
||||
@_generative
|
||||
@_on_conflict_exclusive
|
||||
def on_conflict_do_nothing(
|
||||
self,
|
||||
constraint: _OnConflictConstraintT = None,
|
||||
index_elements: _OnConflictIndexElementsT = None,
|
||||
index_where: _OnConflictIndexWhereT = None,
|
||||
) -> Self:
|
||||
"""
|
||||
Specifies a DO NOTHING action for ON CONFLICT clause.
|
||||
|
||||
The ``constraint`` and ``index_elements`` arguments
|
||||
are optional, but only one of these can be specified.
|
||||
|
||||
:param constraint:
|
||||
The name of a unique or exclusion constraint on the table,
|
||||
or the constraint object itself if it has a .name attribute.
|
||||
|
||||
:param index_elements:
|
||||
A sequence consisting of string column names, :class:`_schema.Column`
|
||||
objects, or other column expression objects that will be used
|
||||
to infer a target index.
|
||||
|
||||
:param index_where:
|
||||
Additional WHERE criterion that can be used to infer a
|
||||
conditional target index.
|
||||
|
||||
.. seealso::
|
||||
|
||||
:ref:`postgresql_insert_on_conflict`
|
||||
|
||||
"""
|
||||
self._post_values_clause = OnConflictDoNothing(
|
||||
constraint, index_elements, index_where
|
||||
)
|
||||
return self
|
||||
|
||||
|
||||
class OnConflictClause(ClauseElement):
|
||||
stringify_dialect = "postgresql"
|
||||
|
||||
constraint_target: Optional[str]
|
||||
inferred_target_elements: Optional[List[Union[str, schema.Column[Any]]]]
|
||||
inferred_target_whereclause: Optional[
|
||||
Union[ColumnElement[Any], TextClause]
|
||||
]
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
constraint: _OnConflictConstraintT = None,
|
||||
index_elements: _OnConflictIndexElementsT = None,
|
||||
index_where: _OnConflictIndexWhereT = None,
|
||||
):
|
||||
if constraint is not None:
|
||||
if not isinstance(constraint, str) and isinstance(
|
||||
constraint,
|
||||
(schema.Constraint, ext.ExcludeConstraint),
|
||||
):
|
||||
constraint = getattr(constraint, "name") or constraint
|
||||
|
||||
if constraint is not None:
|
||||
if index_elements is not None:
|
||||
raise ValueError(
|
||||
"'constraint' and 'index_elements' are mutually exclusive"
|
||||
)
|
||||
|
||||
if isinstance(constraint, str):
|
||||
self.constraint_target = constraint
|
||||
self.inferred_target_elements = None
|
||||
self.inferred_target_whereclause = None
|
||||
elif isinstance(constraint, schema.Index):
|
||||
index_elements = constraint.expressions
|
||||
index_where = constraint.dialect_options["postgresql"].get(
|
||||
"where"
|
||||
)
|
||||
elif isinstance(constraint, ext.ExcludeConstraint):
|
||||
index_elements = constraint.columns
|
||||
index_where = constraint.where
|
||||
else:
|
||||
index_elements = constraint.columns
|
||||
index_where = constraint.dialect_options["postgresql"].get(
|
||||
"where"
|
||||
)
|
||||
|
||||
if index_elements is not None:
|
||||
self.constraint_target = None
|
||||
self.inferred_target_elements = [
|
||||
coercions.expect(roles.DDLConstraintColumnRole, column)
|
||||
for column in index_elements
|
||||
]
|
||||
|
||||
self.inferred_target_whereclause = (
|
||||
coercions.expect(
|
||||
(
|
||||
roles.StatementOptionRole
|
||||
if isinstance(constraint, ext.ExcludeConstraint)
|
||||
else roles.WhereHavingRole
|
||||
),
|
||||
index_where,
|
||||
)
|
||||
if index_where is not None
|
||||
else None
|
||||
)
|
||||
|
||||
elif constraint is None:
|
||||
self.constraint_target = self.inferred_target_elements = (
|
||||
self.inferred_target_whereclause
|
||||
) = None
|
||||
|
||||
|
||||
class OnConflictDoNothing(OnConflictClause):
|
||||
__visit_name__ = "on_conflict_do_nothing"
|
||||
|
||||
|
||||
class OnConflictDoUpdate(OnConflictClause):
|
||||
__visit_name__ = "on_conflict_do_update"
|
||||
|
||||
update_values_to_set: List[Tuple[Union[schema.Column[Any], str], Any]]
|
||||
update_whereclause: Optional[ColumnElement[Any]]
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
constraint: _OnConflictConstraintT = None,
|
||||
index_elements: _OnConflictIndexElementsT = None,
|
||||
index_where: _OnConflictIndexWhereT = None,
|
||||
set_: _OnConflictSetT = None,
|
||||
where: _OnConflictWhereT = None,
|
||||
):
|
||||
super().__init__(
|
||||
constraint=constraint,
|
||||
index_elements=index_elements,
|
||||
index_where=index_where,
|
||||
)
|
||||
|
||||
if (
|
||||
self.inferred_target_elements is None
|
||||
and self.constraint_target is None
|
||||
):
|
||||
raise ValueError(
|
||||
"Either constraint or index_elements, "
|
||||
"but not both, must be specified unless DO NOTHING"
|
||||
)
|
||||
|
||||
if isinstance(set_, dict):
|
||||
if not set_:
|
||||
raise ValueError("set parameter dictionary must not be empty")
|
||||
elif isinstance(set_, ColumnCollection):
|
||||
set_ = dict(set_)
|
||||
else:
|
||||
raise ValueError(
|
||||
"set parameter must be a non-empty dictionary "
|
||||
"or a ColumnCollection such as the `.c.` collection "
|
||||
"of a Table object"
|
||||
)
|
||||
self.update_values_to_set = [
|
||||
(coercions.expect(roles.DMLColumnRole, key), value)
|
||||
for key, value in set_.items()
|
||||
]
|
||||
self.update_whereclause = (
|
||||
coercions.expect(roles.WhereHavingRole, where)
|
||||
if where is not None
|
||||
else None
|
||||
)
|
||||
Reference in New Issue
Block a user