3304 lines
104 KiB
Python
3304 lines
104 KiB
Python
# mssql/base.py
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# Copyright (C) 2005-2021 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""
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.. dialect:: mssql
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:name: Microsoft SQL Server
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:full_support: 2017
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:normal_support: 2012+
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:best_effort: 2005+
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.. _mssql_external_dialects:
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External Dialects
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-----------------
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In addition to the above DBAPI layers with native SQLAlchemy support, there
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are third-party dialects for other DBAPI layers that are compatible
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with SQL Server. See the "External Dialects" list on the
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:ref:`dialect_toplevel` page.
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.. _mssql_identity:
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Auto Increment Behavior / IDENTITY Columns
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------------------------------------------
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SQL Server provides so-called "auto incrementing" behavior using the
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``IDENTITY`` construct, which can be placed on any single integer column in a
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table. SQLAlchemy considers ``IDENTITY`` within its default "autoincrement"
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behavior for an integer primary key column, described at
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:paramref:`_schema.Column.autoincrement`. This means that by default,
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the first
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integer primary key column in a :class:`_schema.Table`
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will be considered to be the
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identity column - unless it is associated with a :class:`.Sequence` - and will
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generate DDL as such::
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from sqlalchemy import Table, MetaData, Column, Integer
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m = MetaData()
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t = Table('t', m,
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Column('id', Integer, primary_key=True),
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Column('x', Integer))
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m.create_all(engine)
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The above example will generate DDL as:
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.. sourcecode:: sql
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CREATE TABLE t (
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id INTEGER NOT NULL IDENTITY,
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x INTEGER NULL,
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PRIMARY KEY (id)
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)
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For the case where this default generation of ``IDENTITY`` is not desired,
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specify ``False`` for the :paramref:`_schema.Column.autoincrement` flag,
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on the first integer primary key column::
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m = MetaData()
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t = Table('t', m,
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Column('id', Integer, primary_key=True, autoincrement=False),
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Column('x', Integer))
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m.create_all(engine)
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To add the ``IDENTITY`` keyword to a non-primary key column, specify
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``True`` for the :paramref:`_schema.Column.autoincrement` flag on the desired
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:class:`_schema.Column` object, and ensure that
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:paramref:`_schema.Column.autoincrement`
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is set to ``False`` on any integer primary key column::
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m = MetaData()
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t = Table('t', m,
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Column('id', Integer, primary_key=True, autoincrement=False),
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Column('x', Integer, autoincrement=True))
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m.create_all(engine)
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.. versionchanged:: 1.4 Added :class:`_schema.Identity` construct
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in a :class:`_schema.Column` to specify the start and increment
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parameters of an IDENTITY. These replace
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the use of the :class:`.Sequence` object in order to specify these values.
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.. deprecated:: 1.4
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The ``mssql_identity_start`` and ``mssql_identity_increment`` parameters
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to :class:`_schema.Column` are deprecated and should we replaced by
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an :class:`_schema.Identity` object. Specifying both ways of configuring
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an IDENTITY will result in a compile error.
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These options are also no longer returned as part of the
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``dialect_options`` key in :meth:`_reflection.Inspector.get_columns`.
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Use the information in the ``identity`` key instead.
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.. deprecated:: 1.3
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The use of :class:`.Sequence` to specify IDENTITY characteristics is
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deprecated and will be removed in a future release. Please use
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the :class:`_schema.Identity` object parameters
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:paramref:`_schema.Identity.start` and
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:paramref:`_schema.Identity.increment`.
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.. versionchanged:: 1.4 Removed the ability to use a :class:`.Sequence`
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object to modify IDENTITY characteristics. :class:`.Sequence` objects
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now only manipulate true T-SQL SEQUENCE types.
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.. note::
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There can only be one IDENTITY column on the table. When using
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``autoincrement=True`` to enable the IDENTITY keyword, SQLAlchemy does not
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guard against multiple columns specifying the option simultaneously. The
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SQL Server database will instead reject the ``CREATE TABLE`` statement.
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.. note::
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An INSERT statement which attempts to provide a value for a column that is
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marked with IDENTITY will be rejected by SQL Server. In order for the
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value to be accepted, a session-level option "SET IDENTITY_INSERT" must be
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enabled. The SQLAlchemy SQL Server dialect will perform this operation
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automatically when using a core :class:`_expression.Insert`
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construct; if the
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execution specifies a value for the IDENTITY column, the "IDENTITY_INSERT"
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option will be enabled for the span of that statement's invocation.However,
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this scenario is not high performing and should not be relied upon for
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normal use. If a table doesn't actually require IDENTITY behavior in its
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integer primary key column, the keyword should be disabled when creating
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the table by ensuring that ``autoincrement=False`` is set.
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Controlling "Start" and "Increment"
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^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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Specific control over the "start" and "increment" values for
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the ``IDENTITY`` generator are provided using the
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:paramref:`_schema.Identity.start` and :paramref:`_schema.Identity.increment`
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parameters passed to the :class:`_schema.Identity` object::
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from sqlalchemy import Table, Integer, Column, Identity
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test = Table(
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'test', metadata,
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Column(
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'id',
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Integer,
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primary_key=True,
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Identity(start=100, increment=10)
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),
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Column('name', String(20))
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)
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The CREATE TABLE for the above :class:`_schema.Table` object would be:
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.. sourcecode:: sql
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CREATE TABLE test (
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id INTEGER NOT NULL IDENTITY(100,10) PRIMARY KEY,
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name VARCHAR(20) NULL,
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)
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.. note::
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The :class:`_schema.Identity` object supports many other parameter in
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addition to ``start`` and ``increment``. These are not supported by
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SQL Server and will be ignored when generating the CREATE TABLE ddl.
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.. versionchanged:: 1.3.19 The :class:`_schema.Identity` object is
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now used to affect the
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``IDENTITY`` generator for a :class:`_schema.Column` under SQL Server.
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Previously, the :class:`.Sequence` object was used. As SQL Server now
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supports real sequences as a separate construct, :class:`.Sequence` will be
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functional in the normal way starting from SQLAlchemy version 1.4.
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INSERT behavior
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^^^^^^^^^^^^^^^^
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Handling of the ``IDENTITY`` column at INSERT time involves two key
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techniques. The most common is being able to fetch the "last inserted value"
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for a given ``IDENTITY`` column, a process which SQLAlchemy performs
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implicitly in many cases, most importantly within the ORM.
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The process for fetching this value has several variants:
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* In the vast majority of cases, RETURNING is used in conjunction with INSERT
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statements on SQL Server in order to get newly generated primary key values:
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.. sourcecode:: sql
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INSERT INTO t (x) OUTPUT inserted.id VALUES (?)
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* When RETURNING is not available or has been disabled via
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``implicit_returning=False``, either the ``scope_identity()`` function or
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the ``@@identity`` variable is used; behavior varies by backend:
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* when using PyODBC, the phrase ``; select scope_identity()`` will be
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appended to the end of the INSERT statement; a second result set will be
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fetched in order to receive the value. Given a table as::
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t = Table('t', m, Column('id', Integer, primary_key=True),
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Column('x', Integer),
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implicit_returning=False)
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an INSERT will look like:
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.. sourcecode:: sql
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INSERT INTO t (x) VALUES (?); select scope_identity()
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* Other dialects such as pymssql will call upon
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``SELECT scope_identity() AS lastrowid`` subsequent to an INSERT
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statement. If the flag ``use_scope_identity=False`` is passed to
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:func:`_sa.create_engine`,
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the statement ``SELECT @@identity AS lastrowid``
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is used instead.
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A table that contains an ``IDENTITY`` column will prohibit an INSERT statement
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that refers to the identity column explicitly. The SQLAlchemy dialect will
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detect when an INSERT construct, created using a core
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:func:`_expression.insert`
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construct (not a plain string SQL), refers to the identity column, and
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in this case will emit ``SET IDENTITY_INSERT ON`` prior to the insert
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statement proceeding, and ``SET IDENTITY_INSERT OFF`` subsequent to the
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execution. Given this example::
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m = MetaData()
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t = Table('t', m, Column('id', Integer, primary_key=True),
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Column('x', Integer))
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m.create_all(engine)
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with engine.begin() as conn:
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conn.execute(t.insert(), {'id': 1, 'x':1}, {'id':2, 'x':2})
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The above column will be created with IDENTITY, however the INSERT statement
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we emit is specifying explicit values. In the echo output we can see
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how SQLAlchemy handles this:
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.. sourcecode:: sql
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CREATE TABLE t (
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id INTEGER NOT NULL IDENTITY(1,1),
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x INTEGER NULL,
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PRIMARY KEY (id)
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)
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COMMIT
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SET IDENTITY_INSERT t ON
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INSERT INTO t (id, x) VALUES (?, ?)
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((1, 1), (2, 2))
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SET IDENTITY_INSERT t OFF
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COMMIT
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This
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is an auxiliary use case suitable for testing and bulk insert scenarios.
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SEQUENCE support
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----------------
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The :class:`.Sequence` object now creates "real" sequences, i.e.,
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``CREATE SEQUENCE``. To provide compatibility with other dialects,
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:class:`.Sequence` defaults to a start value of 1, even though the
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T-SQL defaults is -9223372036854775808.
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.. versionadded:: 1.4.0
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MAX on VARCHAR / NVARCHAR
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-------------------------
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SQL Server supports the special string "MAX" within the
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:class:`_types.VARCHAR` and :class:`_types.NVARCHAR` datatypes,
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to indicate "maximum length possible". The dialect currently handles this as
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a length of "None" in the base type, rather than supplying a
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dialect-specific version of these types, so that a base type
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specified such as ``VARCHAR(None)`` can assume "unlengthed" behavior on
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more than one backend without using dialect-specific types.
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To build a SQL Server VARCHAR or NVARCHAR with MAX length, use None::
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my_table = Table(
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'my_table', metadata,
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Column('my_data', VARCHAR(None)),
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Column('my_n_data', NVARCHAR(None))
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)
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Collation Support
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-----------------
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Character collations are supported by the base string types,
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specified by the string argument "collation"::
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from sqlalchemy import VARCHAR
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Column('login', VARCHAR(32, collation='Latin1_General_CI_AS'))
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When such a column is associated with a :class:`_schema.Table`, the
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CREATE TABLE statement for this column will yield::
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login VARCHAR(32) COLLATE Latin1_General_CI_AS NULL
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LIMIT/OFFSET Support
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--------------------
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MSSQL has added support for LIMIT / OFFSET as of SQL Server 2012, via the
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"OFFSET n ROWS" and "FETCH NEXT n ROWS" clauses. SQLAlchemy supports these
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syntaxes automatically if SQL Server 2012 or greater is detected.
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.. versionchanged:: 1.4 support added for SQL Server "OFFSET n ROWS" and
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"FETCH NEXT n ROWS" syntax.
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For statements that specify only LIMIT and no OFFSET, all versions of SQL
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Server support the TOP keyword. This syntax is used for all SQL Server
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versions when no OFFSET clause is present. A statement such as::
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select(some_table).limit(5)
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will render similarly to::
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SELECT TOP 5 col1, col2.. FROM table
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For versions of SQL Server prior to SQL Server 2012, a statement that uses
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LIMIT and OFFSET, or just OFFSET alone, will be rendered using the
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``ROW_NUMBER()`` window function. A statement such as::
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select(some_table).order_by(some_table.c.col3).limit(5).offset(10)
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will render similarly to::
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SELECT anon_1.col1, anon_1.col2 FROM (SELECT col1, col2,
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ROW_NUMBER() OVER (ORDER BY col3) AS
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mssql_rn FROM table WHERE t.x = :x_1) AS
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anon_1 WHERE mssql_rn > :param_1 AND mssql_rn <= :param_2 + :param_1
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Note that when using LIMIT and/or OFFSET, whether using the older
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or newer SQL Server syntaxes, the statement must have an ORDER BY as well,
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else a :class:`.CompileError` is raised.
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.. _mssql_isolation_level:
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Transaction Isolation Level
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---------------------------
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All SQL Server dialects support setting of transaction isolation level
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both via a dialect-specific parameter
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:paramref:`_sa.create_engine.isolation_level`
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accepted by :func:`_sa.create_engine`,
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as well as the :paramref:`.Connection.execution_options.isolation_level`
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argument as passed to
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:meth:`_engine.Connection.execution_options`.
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This feature works by issuing the
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command ``SET TRANSACTION ISOLATION LEVEL <level>`` for
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each new connection.
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To set isolation level using :func:`_sa.create_engine`::
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engine = create_engine(
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"mssql+pyodbc://scott:tiger@ms_2008",
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isolation_level="REPEATABLE READ"
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)
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To set using per-connection execution options::
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connection = engine.connect()
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connection = connection.execution_options(
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isolation_level="READ COMMITTED"
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)
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Valid values for ``isolation_level`` include:
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* ``AUTOCOMMIT`` - pyodbc / pymssql-specific
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* ``READ COMMITTED``
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* ``READ UNCOMMITTED``
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* ``REPEATABLE READ``
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* ``SERIALIZABLE``
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* ``SNAPSHOT`` - specific to SQL Server
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.. versionadded:: 1.2 added AUTOCOMMIT isolation level setting
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.. seealso::
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:ref:`dbapi_autocommit`
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Nullability
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-----------
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MSSQL has support for three levels of column nullability. The default
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nullability allows nulls and is explicit in the CREATE TABLE
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construct::
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name VARCHAR(20) NULL
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If ``nullable=None`` is specified then no specification is made. In
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other words the database's configured default is used. This will
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render::
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name VARCHAR(20)
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If ``nullable`` is ``True`` or ``False`` then the column will be
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``NULL`` or ``NOT NULL`` respectively.
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Date / Time Handling
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--------------------
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DATE and TIME are supported. Bind parameters are converted
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to datetime.datetime() objects as required by most MSSQL drivers,
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and results are processed from strings if needed.
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The DATE and TIME types are not available for MSSQL 2005 and
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previous - if a server version below 2008 is detected, DDL
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for these types will be issued as DATETIME.
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.. _mssql_large_type_deprecation:
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Large Text/Binary Type Deprecation
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----------------------------------
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Per
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`SQL Server 2012/2014 Documentation <http://technet.microsoft.com/en-us/library/ms187993.aspx>`_,
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the ``NTEXT``, ``TEXT`` and ``IMAGE`` datatypes are to be removed from SQL
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Server in a future release. SQLAlchemy normally relates these types to the
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:class:`.UnicodeText`, :class:`_expression.TextClause` and
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:class:`.LargeBinary` datatypes.
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In order to accommodate this change, a new flag ``deprecate_large_types``
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is added to the dialect, which will be automatically set based on detection
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of the server version in use, if not otherwise set by the user. The
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behavior of this flag is as follows:
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* When this flag is ``True``, the :class:`.UnicodeText`,
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:class:`_expression.TextClause` and
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:class:`.LargeBinary` datatypes, when used to render DDL, will render the
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types ``NVARCHAR(max)``, ``VARCHAR(max)``, and ``VARBINARY(max)``,
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respectively. This is a new behavior as of the addition of this flag.
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* When this flag is ``False``, the :class:`.UnicodeText`,
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:class:`_expression.TextClause` and
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:class:`.LargeBinary` datatypes, when used to render DDL, will render the
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types ``NTEXT``, ``TEXT``, and ``IMAGE``,
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respectively. This is the long-standing behavior of these types.
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* The flag begins with the value ``None``, before a database connection is
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established. If the dialect is used to render DDL without the flag being
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set, it is interpreted the same as ``False``.
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* On first connection, the dialect detects if SQL Server version 2012 or
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greater is in use; if the flag is still at ``None``, it sets it to ``True``
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or ``False`` based on whether 2012 or greater is detected.
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* The flag can be set to either ``True`` or ``False`` when the dialect
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is created, typically via :func:`_sa.create_engine`::
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eng = create_engine("mssql+pymssql://user:pass@host/db",
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deprecate_large_types=True)
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* Complete control over whether the "old" or "new" types are rendered is
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available in all SQLAlchemy versions by using the UPPERCASE type objects
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instead: :class:`_types.NVARCHAR`, :class:`_types.VARCHAR`,
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:class:`_types.VARBINARY`, :class:`_types.TEXT`, :class:`_mssql.NTEXT`,
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:class:`_mssql.IMAGE`
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will always remain fixed and always output exactly that
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type.
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.. versionadded:: 1.0.0
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.. _multipart_schema_names:
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Multipart Schema Names
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----------------------
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SQL Server schemas sometimes require multiple parts to their "schema"
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qualifier, that is, including the database name and owner name as separate
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tokens, such as ``mydatabase.dbo.some_table``. These multipart names can be set
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at once using the :paramref:`_schema.Table.schema` argument of
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:class:`_schema.Table`::
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Table(
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"some_table", metadata,
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Column("q", String(50)),
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schema="mydatabase.dbo"
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)
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When performing operations such as table or component reflection, a schema
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argument that contains a dot will be split into separate
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"database" and "owner" components in order to correctly query the SQL
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Server information schema tables, as these two values are stored separately.
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Additionally, when rendering the schema name for DDL or SQL, the two
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components will be quoted separately for case sensitive names and other
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special characters. Given an argument as below::
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Table(
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"some_table", metadata,
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Column("q", String(50)),
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schema="MyDataBase.dbo"
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)
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The above schema would be rendered as ``[MyDataBase].dbo``, and also in
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reflection, would be reflected using "dbo" as the owner and "MyDataBase"
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as the database name.
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To control how the schema name is broken into database / owner,
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specify brackets (which in SQL Server are quoting characters) in the name.
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Below, the "owner" will be considered as ``MyDataBase.dbo`` and the
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"database" will be None::
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Table(
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"some_table", metadata,
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Column("q", String(50)),
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schema="[MyDataBase.dbo]"
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)
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To individually specify both database and owner name with special characters
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or embedded dots, use two sets of brackets::
|
|
|
|
Table(
|
|
"some_table", metadata,
|
|
Column("q", String(50)),
|
|
schema="[MyDataBase.Period].[MyOwner.Dot]"
|
|
)
|
|
|
|
|
|
.. versionchanged:: 1.2 the SQL Server dialect now treats brackets as
|
|
identifier delimeters splitting the schema into separate database
|
|
and owner tokens, to allow dots within either name itself.
|
|
|
|
.. _legacy_schema_rendering:
|
|
|
|
Legacy Schema Mode
|
|
------------------
|
|
|
|
Very old versions of the MSSQL dialect introduced the behavior such that a
|
|
schema-qualified table would be auto-aliased when used in a
|
|
SELECT statement; given a table::
|
|
|
|
account_table = Table(
|
|
'account', metadata,
|
|
Column('id', Integer, primary_key=True),
|
|
Column('info', String(100)),
|
|
schema="customer_schema"
|
|
)
|
|
|
|
this legacy mode of rendering would assume that "customer_schema.account"
|
|
would not be accepted by all parts of the SQL statement, as illustrated
|
|
below::
|
|
|
|
>>> eng = create_engine("mssql+pymssql://mydsn", legacy_schema_aliasing=True)
|
|
>>> print(account_table.select().compile(eng))
|
|
SELECT account_1.id, account_1.info
|
|
FROM customer_schema.account AS account_1
|
|
|
|
This mode of behavior is now off by default, as it appears to have served
|
|
no purpose; however in the case that legacy applications rely upon it,
|
|
it is available using the ``legacy_schema_aliasing`` argument to
|
|
:func:`_sa.create_engine` as illustrated above.
|
|
|
|
.. versionchanged:: 1.1 the ``legacy_schema_aliasing`` flag introduced
|
|
in version 1.0.5 to allow disabling of legacy mode for schemas now
|
|
defaults to False.
|
|
|
|
.. deprecated:: 1.4
|
|
|
|
The ``legacy_schema_aliasing`` flag is now
|
|
deprecated and will be removed in a future release.
|
|
|
|
.. _mssql_indexes:
|
|
|
|
Clustered Index Support
|
|
-----------------------
|
|
|
|
The MSSQL dialect supports clustered indexes (and primary keys) via the
|
|
``mssql_clustered`` option. This option is available to :class:`.Index`,
|
|
:class:`.UniqueConstraint`. and :class:`.PrimaryKeyConstraint`.
|
|
|
|
To generate a clustered index::
|
|
|
|
Index("my_index", table.c.x, mssql_clustered=True)
|
|
|
|
which renders the index as ``CREATE CLUSTERED INDEX my_index ON table (x)``.
|
|
|
|
To generate a clustered primary key use::
|
|
|
|
Table('my_table', metadata,
|
|
Column('x', ...),
|
|
Column('y', ...),
|
|
PrimaryKeyConstraint("x", "y", mssql_clustered=True))
|
|
|
|
which will render the table, for example, as::
|
|
|
|
CREATE TABLE my_table (x INTEGER NOT NULL, y INTEGER NOT NULL,
|
|
PRIMARY KEY CLUSTERED (x, y))
|
|
|
|
Similarly, we can generate a clustered unique constraint using::
|
|
|
|
Table('my_table', metadata,
|
|
Column('x', ...),
|
|
Column('y', ...),
|
|
PrimaryKeyConstraint("x"),
|
|
UniqueConstraint("y", mssql_clustered=True),
|
|
)
|
|
|
|
To explicitly request a non-clustered primary key (for example, when
|
|
a separate clustered index is desired), use::
|
|
|
|
Table('my_table', metadata,
|
|
Column('x', ...),
|
|
Column('y', ...),
|
|
PrimaryKeyConstraint("x", "y", mssql_clustered=False))
|
|
|
|
which will render the table, for example, as::
|
|
|
|
CREATE TABLE my_table (x INTEGER NOT NULL, y INTEGER NOT NULL,
|
|
PRIMARY KEY NONCLUSTERED (x, y))
|
|
|
|
.. versionchanged:: 1.1 the ``mssql_clustered`` option now defaults
|
|
to None, rather than False. ``mssql_clustered=False`` now explicitly
|
|
renders the NONCLUSTERED clause, whereas None omits the CLUSTERED
|
|
clause entirely, allowing SQL Server defaults to take effect.
|
|
|
|
|
|
MSSQL-Specific Index Options
|
|
-----------------------------
|
|
|
|
In addition to clustering, the MSSQL dialect supports other special options
|
|
for :class:`.Index`.
|
|
|
|
INCLUDE
|
|
^^^^^^^
|
|
|
|
The ``mssql_include`` option renders INCLUDE(colname) for the given string
|
|
names::
|
|
|
|
Index("my_index", table.c.x, mssql_include=['y'])
|
|
|
|
would render the index as ``CREATE INDEX my_index ON table (x) INCLUDE (y)``
|
|
|
|
.. _mssql_index_where:
|
|
|
|
Filtered Indexes
|
|
^^^^^^^^^^^^^^^^
|
|
|
|
The ``mssql_where`` option renders WHERE(condition) for the given string
|
|
names::
|
|
|
|
Index("my_index", table.c.x, mssql_where=table.c.x > 10)
|
|
|
|
would render the index as ``CREATE INDEX my_index ON table (x) WHERE x > 10``.
|
|
|
|
.. versionadded:: 1.3.4
|
|
|
|
Index ordering
|
|
^^^^^^^^^^^^^^
|
|
|
|
Index ordering is available via functional expressions, such as::
|
|
|
|
Index("my_index", table.c.x.desc())
|
|
|
|
would render the index as ``CREATE INDEX my_index ON table (x DESC)``
|
|
|
|
.. seealso::
|
|
|
|
:ref:`schema_indexes_functional`
|
|
|
|
Compatibility Levels
|
|
--------------------
|
|
MSSQL supports the notion of setting compatibility levels at the
|
|
database level. This allows, for instance, to run a database that
|
|
is compatible with SQL2000 while running on a SQL2005 database
|
|
server. ``server_version_info`` will always return the database
|
|
server version information (in this case SQL2005) and not the
|
|
compatibility level information. Because of this, if running under
|
|
a backwards compatibility mode SQLAlchemy may attempt to use T-SQL
|
|
statements that are unable to be parsed by the database server.
|
|
|
|
Triggers
|
|
--------
|
|
|
|
SQLAlchemy by default uses OUTPUT INSERTED to get at newly
|
|
generated primary key values via IDENTITY columns or other
|
|
server side defaults. MS-SQL does not
|
|
allow the usage of OUTPUT INSERTED on tables that have triggers.
|
|
To disable the usage of OUTPUT INSERTED on a per-table basis,
|
|
specify ``implicit_returning=False`` for each :class:`_schema.Table`
|
|
which has triggers::
|
|
|
|
Table('mytable', metadata,
|
|
Column('id', Integer, primary_key=True),
|
|
# ...,
|
|
implicit_returning=False
|
|
)
|
|
|
|
Declarative form::
|
|
|
|
class MyClass(Base):
|
|
# ...
|
|
__table_args__ = {'implicit_returning':False}
|
|
|
|
|
|
This option can also be specified engine-wide using the
|
|
``implicit_returning=False`` argument on :func:`_sa.create_engine`.
|
|
|
|
.. _mssql_rowcount_versioning:
|
|
|
|
Rowcount Support / ORM Versioning
|
|
---------------------------------
|
|
|
|
The SQL Server drivers may have limited ability to return the number
|
|
of rows updated from an UPDATE or DELETE statement.
|
|
|
|
As of this writing, the PyODBC driver is not able to return a rowcount when
|
|
OUTPUT INSERTED is used. This impacts the SQLAlchemy ORM's versioning feature
|
|
in many cases where server-side value generators are in use in that while the
|
|
versioning operations can succeed, the ORM cannot always check that an UPDATE
|
|
or DELETE statement matched the number of rows expected, which is how it
|
|
verifies that the version identifier matched. When this condition occurs, a
|
|
warning will be emitted but the operation will proceed.
|
|
|
|
The use of OUTPUT INSERTED can be disabled by setting the
|
|
:paramref:`_schema.Table.implicit_returning` flag to ``False`` on a particular
|
|
:class:`_schema.Table`, which in declarative looks like::
|
|
|
|
class MyTable(Base):
|
|
__tablename__ = 'mytable'
|
|
id = Column(Integer, primary_key=True)
|
|
stuff = Column(String(10))
|
|
timestamp = Column(TIMESTAMP(), default=text('DEFAULT'))
|
|
__mapper_args__ = {
|
|
'version_id_col': timestamp,
|
|
'version_id_generator': False,
|
|
}
|
|
__table_args__ = {
|
|
'implicit_returning': False
|
|
}
|
|
|
|
Enabling Snapshot Isolation
|
|
---------------------------
|
|
|
|
SQL Server has a default transaction
|
|
isolation mode that locks entire tables, and causes even mildly concurrent
|
|
applications to have long held locks and frequent deadlocks.
|
|
Enabling snapshot isolation for the database as a whole is recommended
|
|
for modern levels of concurrency support. This is accomplished via the
|
|
following ALTER DATABASE commands executed at the SQL prompt::
|
|
|
|
ALTER DATABASE MyDatabase SET ALLOW_SNAPSHOT_ISOLATION ON
|
|
|
|
ALTER DATABASE MyDatabase SET READ_COMMITTED_SNAPSHOT ON
|
|
|
|
Background on SQL Server snapshot isolation is available at
|
|
http://msdn.microsoft.com/en-us/library/ms175095.aspx.
|
|
|
|
""" # noqa
|
|
|
|
import codecs
|
|
import datetime
|
|
import operator
|
|
import re
|
|
|
|
from . import information_schema as ischema
|
|
from .json import JSON
|
|
from .json import JSONIndexType
|
|
from .json import JSONPathType
|
|
from ... import exc
|
|
from ... import Identity
|
|
from ... import schema as sa_schema
|
|
from ... import Sequence
|
|
from ... import sql
|
|
from ... import types as sqltypes
|
|
from ... import util
|
|
from ...engine import cursor as _cursor
|
|
from ...engine import default
|
|
from ...engine import reflection
|
|
from ...sql import coercions
|
|
from ...sql import compiler
|
|
from ...sql import elements
|
|
from ...sql import expression
|
|
from ...sql import func
|
|
from ...sql import quoted_name
|
|
from ...sql import roles
|
|
from ...sql import util as sql_util
|
|
from ...types import BIGINT
|
|
from ...types import BINARY
|
|
from ...types import CHAR
|
|
from ...types import DATE
|
|
from ...types import DATETIME
|
|
from ...types import DECIMAL
|
|
from ...types import FLOAT
|
|
from ...types import INTEGER
|
|
from ...types import NCHAR
|
|
from ...types import NUMERIC
|
|
from ...types import NVARCHAR
|
|
from ...types import SMALLINT
|
|
from ...types import TEXT
|
|
from ...types import VARCHAR
|
|
from ...util import compat
|
|
from ...util import update_wrapper
|
|
from ...util.langhelpers import public_factory
|
|
|
|
|
|
# http://sqlserverbuilds.blogspot.com/
|
|
MS_2017_VERSION = (14,)
|
|
MS_2016_VERSION = (13,)
|
|
MS_2014_VERSION = (12,)
|
|
MS_2012_VERSION = (11,)
|
|
MS_2008_VERSION = (10,)
|
|
MS_2005_VERSION = (9,)
|
|
MS_2000_VERSION = (8,)
|
|
|
|
RESERVED_WORDS = set(
|
|
[
|
|
"add",
|
|
"all",
|
|
"alter",
|
|
"and",
|
|
"any",
|
|
"as",
|
|
"asc",
|
|
"authorization",
|
|
"backup",
|
|
"begin",
|
|
"between",
|
|
"break",
|
|
"browse",
|
|
"bulk",
|
|
"by",
|
|
"cascade",
|
|
"case",
|
|
"check",
|
|
"checkpoint",
|
|
"close",
|
|
"clustered",
|
|
"coalesce",
|
|
"collate",
|
|
"column",
|
|
"commit",
|
|
"compute",
|
|
"constraint",
|
|
"contains",
|
|
"containstable",
|
|
"continue",
|
|
"convert",
|
|
"create",
|
|
"cross",
|
|
"current",
|
|
"current_date",
|
|
"current_time",
|
|
"current_timestamp",
|
|
"current_user",
|
|
"cursor",
|
|
"database",
|
|
"dbcc",
|
|
"deallocate",
|
|
"declare",
|
|
"default",
|
|
"delete",
|
|
"deny",
|
|
"desc",
|
|
"disk",
|
|
"distinct",
|
|
"distributed",
|
|
"double",
|
|
"drop",
|
|
"dump",
|
|
"else",
|
|
"end",
|
|
"errlvl",
|
|
"escape",
|
|
"except",
|
|
"exec",
|
|
"execute",
|
|
"exists",
|
|
"exit",
|
|
"external",
|
|
"fetch",
|
|
"file",
|
|
"fillfactor",
|
|
"for",
|
|
"foreign",
|
|
"freetext",
|
|
"freetexttable",
|
|
"from",
|
|
"full",
|
|
"function",
|
|
"goto",
|
|
"grant",
|
|
"group",
|
|
"having",
|
|
"holdlock",
|
|
"identity",
|
|
"identity_insert",
|
|
"identitycol",
|
|
"if",
|
|
"in",
|
|
"index",
|
|
"inner",
|
|
"insert",
|
|
"intersect",
|
|
"into",
|
|
"is",
|
|
"join",
|
|
"key",
|
|
"kill",
|
|
"left",
|
|
"like",
|
|
"lineno",
|
|
"load",
|
|
"merge",
|
|
"national",
|
|
"nocheck",
|
|
"nonclustered",
|
|
"not",
|
|
"null",
|
|
"nullif",
|
|
"of",
|
|
"off",
|
|
"offsets",
|
|
"on",
|
|
"open",
|
|
"opendatasource",
|
|
"openquery",
|
|
"openrowset",
|
|
"openxml",
|
|
"option",
|
|
"or",
|
|
"order",
|
|
"outer",
|
|
"over",
|
|
"percent",
|
|
"pivot",
|
|
"plan",
|
|
"precision",
|
|
"primary",
|
|
"print",
|
|
"proc",
|
|
"procedure",
|
|
"public",
|
|
"raiserror",
|
|
"read",
|
|
"readtext",
|
|
"reconfigure",
|
|
"references",
|
|
"replication",
|
|
"restore",
|
|
"restrict",
|
|
"return",
|
|
"revert",
|
|
"revoke",
|
|
"right",
|
|
"rollback",
|
|
"rowcount",
|
|
"rowguidcol",
|
|
"rule",
|
|
"save",
|
|
"schema",
|
|
"securityaudit",
|
|
"select",
|
|
"session_user",
|
|
"set",
|
|
"setuser",
|
|
"shutdown",
|
|
"some",
|
|
"statistics",
|
|
"system_user",
|
|
"table",
|
|
"tablesample",
|
|
"textsize",
|
|
"then",
|
|
"to",
|
|
"top",
|
|
"tran",
|
|
"transaction",
|
|
"trigger",
|
|
"truncate",
|
|
"tsequal",
|
|
"union",
|
|
"unique",
|
|
"unpivot",
|
|
"update",
|
|
"updatetext",
|
|
"use",
|
|
"user",
|
|
"values",
|
|
"varying",
|
|
"view",
|
|
"waitfor",
|
|
"when",
|
|
"where",
|
|
"while",
|
|
"with",
|
|
"writetext",
|
|
]
|
|
)
|
|
|
|
|
|
class REAL(sqltypes.REAL):
|
|
__visit_name__ = "REAL"
|
|
|
|
def __init__(self, **kw):
|
|
# REAL is a synonym for FLOAT(24) on SQL server.
|
|
# it is only accepted as the word "REAL" in DDL, the numeric
|
|
# precision value is not allowed to be present
|
|
kw.setdefault("precision", 24)
|
|
super(REAL, self).__init__(**kw)
|
|
|
|
|
|
class TINYINT(sqltypes.Integer):
|
|
__visit_name__ = "TINYINT"
|
|
|
|
|
|
# MSSQL DATE/TIME types have varied behavior, sometimes returning
|
|
# strings. MSDate/TIME check for everything, and always
|
|
# filter bind parameters into datetime objects (required by pyodbc,
|
|
# not sure about other dialects).
|
|
|
|
|
|
class _MSDate(sqltypes.Date):
|
|
def bind_processor(self, dialect):
|
|
def process(value):
|
|
if type(value) == datetime.date:
|
|
return datetime.datetime(value.year, value.month, value.day)
|
|
else:
|
|
return value
|
|
|
|
return process
|
|
|
|
_reg = re.compile(r"(\d+)-(\d+)-(\d+)")
|
|
|
|
def result_processor(self, dialect, coltype):
|
|
def process(value):
|
|
if isinstance(value, datetime.datetime):
|
|
return value.date()
|
|
elif isinstance(value, util.string_types):
|
|
m = self._reg.match(value)
|
|
if not m:
|
|
raise ValueError(
|
|
"could not parse %r as a date value" % (value,)
|
|
)
|
|
return datetime.date(*[int(x or 0) for x in m.groups()])
|
|
else:
|
|
return value
|
|
|
|
return process
|
|
|
|
|
|
class TIME(sqltypes.TIME):
|
|
def __init__(self, precision=None, **kwargs):
|
|
self.precision = precision
|
|
super(TIME, self).__init__()
|
|
|
|
__zero_date = datetime.date(1900, 1, 1)
|
|
|
|
def bind_processor(self, dialect):
|
|
def process(value):
|
|
if isinstance(value, datetime.datetime):
|
|
value = datetime.datetime.combine(
|
|
self.__zero_date, value.time()
|
|
)
|
|
elif isinstance(value, datetime.time):
|
|
"""issue #5339
|
|
per: https://github.com/mkleehammer/pyodbc/wiki/Tips-and-Tricks-by-Database-Platform#time-columns
|
|
pass TIME value as string
|
|
""" # noqa
|
|
value = str(value)
|
|
return value
|
|
|
|
return process
|
|
|
|
_reg = re.compile(r"(\d+):(\d+):(\d+)(?:\.(\d{0,6}))?")
|
|
|
|
def result_processor(self, dialect, coltype):
|
|
def process(value):
|
|
if isinstance(value, datetime.datetime):
|
|
return value.time()
|
|
elif isinstance(value, util.string_types):
|
|
m = self._reg.match(value)
|
|
if not m:
|
|
raise ValueError(
|
|
"could not parse %r as a time value" % (value,)
|
|
)
|
|
return datetime.time(*[int(x or 0) for x in m.groups()])
|
|
else:
|
|
return value
|
|
|
|
return process
|
|
|
|
|
|
_MSTime = TIME
|
|
|
|
|
|
class _DateTimeBase(object):
|
|
def bind_processor(self, dialect):
|
|
def process(value):
|
|
if type(value) == datetime.date:
|
|
return datetime.datetime(value.year, value.month, value.day)
|
|
else:
|
|
return value
|
|
|
|
return process
|
|
|
|
|
|
class _MSDateTime(_DateTimeBase, sqltypes.DateTime):
|
|
pass
|
|
|
|
|
|
class SMALLDATETIME(_DateTimeBase, sqltypes.DateTime):
|
|
__visit_name__ = "SMALLDATETIME"
|
|
|
|
|
|
class DATETIME2(_DateTimeBase, sqltypes.DateTime):
|
|
__visit_name__ = "DATETIME2"
|
|
|
|
def __init__(self, precision=None, **kw):
|
|
super(DATETIME2, self).__init__(**kw)
|
|
self.precision = precision
|
|
|
|
|
|
class DATETIMEOFFSET(_DateTimeBase, sqltypes.DateTime):
|
|
__visit_name__ = "DATETIMEOFFSET"
|
|
|
|
def __init__(self, precision=None, **kw):
|
|
super(DATETIMEOFFSET, self).__init__(**kw)
|
|
self.precision = precision
|
|
|
|
|
|
class _UnicodeLiteral(object):
|
|
def literal_processor(self, dialect):
|
|
def process(value):
|
|
|
|
value = value.replace("'", "''")
|
|
|
|
if dialect.identifier_preparer._double_percents:
|
|
value = value.replace("%", "%%")
|
|
|
|
return "N'%s'" % value
|
|
|
|
return process
|
|
|
|
|
|
class _MSUnicode(_UnicodeLiteral, sqltypes.Unicode):
|
|
pass
|
|
|
|
|
|
class _MSUnicodeText(_UnicodeLiteral, sqltypes.UnicodeText):
|
|
pass
|
|
|
|
|
|
class TIMESTAMP(sqltypes._Binary):
|
|
"""Implement the SQL Server TIMESTAMP type.
|
|
|
|
Note this is **completely different** than the SQL Standard
|
|
TIMESTAMP type, which is not supported by SQL Server. It
|
|
is a read-only datatype that does not support INSERT of values.
|
|
|
|
.. versionadded:: 1.2
|
|
|
|
.. seealso::
|
|
|
|
:class:`_mssql.ROWVERSION`
|
|
|
|
"""
|
|
|
|
__visit_name__ = "TIMESTAMP"
|
|
|
|
# expected by _Binary to be present
|
|
length = None
|
|
|
|
def __init__(self, convert_int=False):
|
|
"""Construct a TIMESTAMP or ROWVERSION type.
|
|
|
|
:param convert_int: if True, binary integer values will
|
|
be converted to integers on read.
|
|
|
|
.. versionadded:: 1.2
|
|
|
|
"""
|
|
self.convert_int = convert_int
|
|
|
|
def result_processor(self, dialect, coltype):
|
|
super_ = super(TIMESTAMP, self).result_processor(dialect, coltype)
|
|
if self.convert_int:
|
|
|
|
def process(value):
|
|
value = super_(value)
|
|
if value is not None:
|
|
# https://stackoverflow.com/a/30403242/34549
|
|
value = int(codecs.encode(value, "hex"), 16)
|
|
return value
|
|
|
|
return process
|
|
else:
|
|
return super_
|
|
|
|
|
|
class ROWVERSION(TIMESTAMP):
|
|
"""Implement the SQL Server ROWVERSION type.
|
|
|
|
The ROWVERSION datatype is a SQL Server synonym for the TIMESTAMP
|
|
datatype, however current SQL Server documentation suggests using
|
|
ROWVERSION for new datatypes going forward.
|
|
|
|
The ROWVERSION datatype does **not** reflect (e.g. introspect) from the
|
|
database as itself; the returned datatype will be
|
|
:class:`_mssql.TIMESTAMP`.
|
|
|
|
This is a read-only datatype that does not support INSERT of values.
|
|
|
|
.. versionadded:: 1.2
|
|
|
|
.. seealso::
|
|
|
|
:class:`_mssql.TIMESTAMP`
|
|
|
|
"""
|
|
|
|
__visit_name__ = "ROWVERSION"
|
|
|
|
|
|
class NTEXT(sqltypes.UnicodeText):
|
|
|
|
"""MSSQL NTEXT type, for variable-length unicode text up to 2^30
|
|
characters."""
|
|
|
|
__visit_name__ = "NTEXT"
|
|
|
|
|
|
class VARBINARY(sqltypes.VARBINARY, sqltypes.LargeBinary):
|
|
"""The MSSQL VARBINARY type.
|
|
|
|
This type is present to support "deprecate_large_types" mode where
|
|
either ``VARBINARY(max)`` or IMAGE is rendered. Otherwise, this type
|
|
object is redundant vs. :class:`_types.VARBINARY`.
|
|
|
|
.. versionadded:: 1.0.0
|
|
|
|
.. seealso::
|
|
|
|
:ref:`mssql_large_type_deprecation`
|
|
|
|
|
|
|
|
"""
|
|
|
|
__visit_name__ = "VARBINARY"
|
|
|
|
|
|
class IMAGE(sqltypes.LargeBinary):
|
|
__visit_name__ = "IMAGE"
|
|
|
|
|
|
class XML(sqltypes.Text):
|
|
"""MSSQL XML type.
|
|
|
|
This is a placeholder type for reflection purposes that does not include
|
|
any Python-side datatype support. It also does not currently support
|
|
additional arguments, such as "CONTENT", "DOCUMENT",
|
|
"xml_schema_collection".
|
|
|
|
.. versionadded:: 1.1.11
|
|
|
|
"""
|
|
|
|
__visit_name__ = "XML"
|
|
|
|
|
|
class BIT(sqltypes.Boolean):
|
|
"""MSSQL BIT type.
|
|
|
|
Both pyodbc and pymssql return values from BIT columns as
|
|
Python <class 'bool'> so just subclass Boolean.
|
|
|
|
"""
|
|
|
|
__visit_name__ = "BIT"
|
|
|
|
|
|
class MONEY(sqltypes.TypeEngine):
|
|
__visit_name__ = "MONEY"
|
|
|
|
|
|
class SMALLMONEY(sqltypes.TypeEngine):
|
|
__visit_name__ = "SMALLMONEY"
|
|
|
|
|
|
class UNIQUEIDENTIFIER(sqltypes.TypeEngine):
|
|
__visit_name__ = "UNIQUEIDENTIFIER"
|
|
|
|
|
|
class SQL_VARIANT(sqltypes.TypeEngine):
|
|
__visit_name__ = "SQL_VARIANT"
|
|
|
|
|
|
class TryCast(sql.elements.Cast):
|
|
"""Represent a SQL Server TRY_CAST expression."""
|
|
|
|
__visit_name__ = "try_cast"
|
|
|
|
stringify_dialect = "mssql"
|
|
|
|
def __init__(self, *arg, **kw):
|
|
"""Create a TRY_CAST expression.
|
|
|
|
:class:`.TryCast` is a subclass of SQLAlchemy's :class:`.Cast`
|
|
construct, and works in the same way, except that the SQL expression
|
|
rendered is "TRY_CAST" rather than "CAST"::
|
|
|
|
from sqlalchemy import select
|
|
from sqlalchemy import Numeric
|
|
from sqlalchemy.dialects.mssql import try_cast
|
|
|
|
stmt = select(
|
|
try_cast(product_table.c.unit_price, Numeric(10, 4))
|
|
)
|
|
|
|
The above would render::
|
|
|
|
SELECT TRY_CAST (product_table.unit_price AS NUMERIC(10, 4))
|
|
FROM product_table
|
|
|
|
.. versionadded:: 1.3.7
|
|
|
|
"""
|
|
super(TryCast, self).__init__(*arg, **kw)
|
|
|
|
|
|
try_cast = public_factory(TryCast, ".dialects.mssql.try_cast")
|
|
|
|
# old names.
|
|
MSDateTime = _MSDateTime
|
|
MSDate = _MSDate
|
|
MSReal = REAL
|
|
MSTinyInteger = TINYINT
|
|
MSTime = TIME
|
|
MSSmallDateTime = SMALLDATETIME
|
|
MSDateTime2 = DATETIME2
|
|
MSDateTimeOffset = DATETIMEOFFSET
|
|
MSText = TEXT
|
|
MSNText = NTEXT
|
|
MSString = VARCHAR
|
|
MSNVarchar = NVARCHAR
|
|
MSChar = CHAR
|
|
MSNChar = NCHAR
|
|
MSBinary = BINARY
|
|
MSVarBinary = VARBINARY
|
|
MSImage = IMAGE
|
|
MSBit = BIT
|
|
MSMoney = MONEY
|
|
MSSmallMoney = SMALLMONEY
|
|
MSUniqueIdentifier = UNIQUEIDENTIFIER
|
|
MSVariant = SQL_VARIANT
|
|
|
|
ischema_names = {
|
|
"int": INTEGER,
|
|
"bigint": BIGINT,
|
|
"smallint": SMALLINT,
|
|
"tinyint": TINYINT,
|
|
"varchar": VARCHAR,
|
|
"nvarchar": NVARCHAR,
|
|
"char": CHAR,
|
|
"nchar": NCHAR,
|
|
"text": TEXT,
|
|
"ntext": NTEXT,
|
|
"decimal": DECIMAL,
|
|
"numeric": NUMERIC,
|
|
"float": FLOAT,
|
|
"datetime": DATETIME,
|
|
"datetime2": DATETIME2,
|
|
"datetimeoffset": DATETIMEOFFSET,
|
|
"date": DATE,
|
|
"time": TIME,
|
|
"smalldatetime": SMALLDATETIME,
|
|
"binary": BINARY,
|
|
"varbinary": VARBINARY,
|
|
"bit": BIT,
|
|
"real": REAL,
|
|
"image": IMAGE,
|
|
"xml": XML,
|
|
"timestamp": TIMESTAMP,
|
|
"money": MONEY,
|
|
"smallmoney": SMALLMONEY,
|
|
"uniqueidentifier": UNIQUEIDENTIFIER,
|
|
"sql_variant": SQL_VARIANT,
|
|
}
|
|
|
|
|
|
class MSTypeCompiler(compiler.GenericTypeCompiler):
|
|
def _extend(self, spec, type_, length=None):
|
|
"""Extend a string-type declaration with standard SQL
|
|
COLLATE annotations.
|
|
|
|
"""
|
|
|
|
if getattr(type_, "collation", None):
|
|
collation = "COLLATE %s" % type_.collation
|
|
else:
|
|
collation = None
|
|
|
|
if not length:
|
|
length = type_.length
|
|
|
|
if length:
|
|
spec = spec + "(%s)" % length
|
|
|
|
return " ".join([c for c in (spec, collation) if c is not None])
|
|
|
|
def visit_FLOAT(self, type_, **kw):
|
|
precision = getattr(type_, "precision", None)
|
|
if precision is None:
|
|
return "FLOAT"
|
|
else:
|
|
return "FLOAT(%(precision)s)" % {"precision": precision}
|
|
|
|
def visit_TINYINT(self, type_, **kw):
|
|
return "TINYINT"
|
|
|
|
def visit_TIME(self, type_, **kw):
|
|
precision = getattr(type_, "precision", None)
|
|
if precision is not None:
|
|
return "TIME(%s)" % precision
|
|
else:
|
|
return "TIME"
|
|
|
|
def visit_TIMESTAMP(self, type_, **kw):
|
|
return "TIMESTAMP"
|
|
|
|
def visit_ROWVERSION(self, type_, **kw):
|
|
return "ROWVERSION"
|
|
|
|
def visit_datetime(self, type_, **kw):
|
|
if type_.timezone:
|
|
return self.visit_DATETIMEOFFSET(type_, **kw)
|
|
else:
|
|
return self.visit_DATETIME(type_, **kw)
|
|
|
|
def visit_DATETIMEOFFSET(self, type_, **kw):
|
|
precision = getattr(type_, "precision", None)
|
|
if precision is not None:
|
|
return "DATETIMEOFFSET(%s)" % type_.precision
|
|
else:
|
|
return "DATETIMEOFFSET"
|
|
|
|
def visit_DATETIME2(self, type_, **kw):
|
|
precision = getattr(type_, "precision", None)
|
|
if precision is not None:
|
|
return "DATETIME2(%s)" % precision
|
|
else:
|
|
return "DATETIME2"
|
|
|
|
def visit_SMALLDATETIME(self, type_, **kw):
|
|
return "SMALLDATETIME"
|
|
|
|
def visit_unicode(self, type_, **kw):
|
|
return self.visit_NVARCHAR(type_, **kw)
|
|
|
|
def visit_text(self, type_, **kw):
|
|
if self.dialect.deprecate_large_types:
|
|
return self.visit_VARCHAR(type_, **kw)
|
|
else:
|
|
return self.visit_TEXT(type_, **kw)
|
|
|
|
def visit_unicode_text(self, type_, **kw):
|
|
if self.dialect.deprecate_large_types:
|
|
return self.visit_NVARCHAR(type_, **kw)
|
|
else:
|
|
return self.visit_NTEXT(type_, **kw)
|
|
|
|
def visit_NTEXT(self, type_, **kw):
|
|
return self._extend("NTEXT", type_)
|
|
|
|
def visit_TEXT(self, type_, **kw):
|
|
return self._extend("TEXT", type_)
|
|
|
|
def visit_VARCHAR(self, type_, **kw):
|
|
return self._extend("VARCHAR", type_, length=type_.length or "max")
|
|
|
|
def visit_CHAR(self, type_, **kw):
|
|
return self._extend("CHAR", type_)
|
|
|
|
def visit_NCHAR(self, type_, **kw):
|
|
return self._extend("NCHAR", type_)
|
|
|
|
def visit_NVARCHAR(self, type_, **kw):
|
|
return self._extend("NVARCHAR", type_, length=type_.length or "max")
|
|
|
|
def visit_date(self, type_, **kw):
|
|
if self.dialect.server_version_info < MS_2008_VERSION:
|
|
return self.visit_DATETIME(type_, **kw)
|
|
else:
|
|
return self.visit_DATE(type_, **kw)
|
|
|
|
def visit_time(self, type_, **kw):
|
|
if self.dialect.server_version_info < MS_2008_VERSION:
|
|
return self.visit_DATETIME(type_, **kw)
|
|
else:
|
|
return self.visit_TIME(type_, **kw)
|
|
|
|
def visit_large_binary(self, type_, **kw):
|
|
if self.dialect.deprecate_large_types:
|
|
return self.visit_VARBINARY(type_, **kw)
|
|
else:
|
|
return self.visit_IMAGE(type_, **kw)
|
|
|
|
def visit_IMAGE(self, type_, **kw):
|
|
return "IMAGE"
|
|
|
|
def visit_XML(self, type_, **kw):
|
|
return "XML"
|
|
|
|
def visit_VARBINARY(self, type_, **kw):
|
|
return self._extend("VARBINARY", type_, length=type_.length or "max")
|
|
|
|
def visit_boolean(self, type_, **kw):
|
|
return self.visit_BIT(type_)
|
|
|
|
def visit_BIT(self, type_, **kw):
|
|
return "BIT"
|
|
|
|
def visit_JSON(self, type_, **kw):
|
|
# this is a bit of a break with SQLAlchemy's convention of
|
|
# "UPPERCASE name goes to UPPERCASE type name with no modification"
|
|
return self._extend("NVARCHAR", type_, length="max")
|
|
|
|
def visit_MONEY(self, type_, **kw):
|
|
return "MONEY"
|
|
|
|
def visit_SMALLMONEY(self, type_, **kw):
|
|
return "SMALLMONEY"
|
|
|
|
def visit_UNIQUEIDENTIFIER(self, type_, **kw):
|
|
return "UNIQUEIDENTIFIER"
|
|
|
|
def visit_SQL_VARIANT(self, type_, **kw):
|
|
return "SQL_VARIANT"
|
|
|
|
|
|
class MSExecutionContext(default.DefaultExecutionContext):
|
|
_enable_identity_insert = False
|
|
_select_lastrowid = False
|
|
_lastrowid = None
|
|
_rowcount = None
|
|
_result_strategy = None
|
|
|
|
def _opt_encode(self, statement):
|
|
|
|
if not self.dialect.supports_unicode_statements:
|
|
encoded = self.dialect._encoder(statement)[0]
|
|
else:
|
|
encoded = statement
|
|
|
|
if self.compiled and self.compiled.schema_translate_map:
|
|
|
|
rst = self.compiled.preparer._render_schema_translates
|
|
encoded = rst(encoded, self.compiled.schema_translate_map)
|
|
|
|
return encoded
|
|
|
|
def pre_exec(self):
|
|
"""Activate IDENTITY_INSERT if needed."""
|
|
|
|
if self.isinsert:
|
|
tbl = self.compiled.compile_state.dml_table
|
|
id_column = tbl._autoincrement_column
|
|
insert_has_identity = (id_column is not None) and (
|
|
not isinstance(id_column.default, Sequence)
|
|
)
|
|
|
|
if insert_has_identity:
|
|
compile_state = self.compiled.compile_state
|
|
self._enable_identity_insert = (
|
|
id_column.key in self.compiled_parameters[0]
|
|
) or (
|
|
compile_state._dict_parameters
|
|
and (
|
|
id_column.key in compile_state._dict_parameters
|
|
or id_column in compile_state._dict_parameters
|
|
)
|
|
)
|
|
|
|
else:
|
|
self._enable_identity_insert = False
|
|
|
|
self._select_lastrowid = (
|
|
not self.compiled.inline
|
|
and insert_has_identity
|
|
and not self.compiled.returning
|
|
and not self._enable_identity_insert
|
|
and not self.executemany
|
|
)
|
|
|
|
if self._enable_identity_insert:
|
|
self.root_connection._cursor_execute(
|
|
self.cursor,
|
|
self._opt_encode(
|
|
"SET IDENTITY_INSERT %s ON"
|
|
% self.identifier_preparer.format_table(tbl)
|
|
),
|
|
(),
|
|
self,
|
|
)
|
|
|
|
def post_exec(self):
|
|
"""Disable IDENTITY_INSERT if enabled."""
|
|
|
|
conn = self.root_connection
|
|
|
|
if self.isinsert or self.isupdate or self.isdelete:
|
|
self._rowcount = self.cursor.rowcount
|
|
|
|
if self._select_lastrowid:
|
|
if self.dialect.use_scope_identity:
|
|
conn._cursor_execute(
|
|
self.cursor,
|
|
"SELECT scope_identity() AS lastrowid",
|
|
(),
|
|
self,
|
|
)
|
|
else:
|
|
conn._cursor_execute(
|
|
self.cursor, "SELECT @@identity AS lastrowid", (), self
|
|
)
|
|
# fetchall() ensures the cursor is consumed without closing it
|
|
row = self.cursor.fetchall()[0]
|
|
self._lastrowid = int(row[0])
|
|
|
|
elif (
|
|
self.isinsert or self.isupdate or self.isdelete
|
|
) and self.compiled.returning:
|
|
self.cursor_fetch_strategy = (
|
|
_cursor.FullyBufferedCursorFetchStrategy(
|
|
self.cursor,
|
|
self.cursor.description,
|
|
self.cursor.fetchall(),
|
|
)
|
|
)
|
|
|
|
if self._enable_identity_insert:
|
|
conn._cursor_execute(
|
|
self.cursor,
|
|
self._opt_encode(
|
|
"SET IDENTITY_INSERT %s OFF"
|
|
% self.identifier_preparer.format_table(
|
|
self.compiled.compile_state.dml_table
|
|
)
|
|
),
|
|
(),
|
|
self,
|
|
)
|
|
|
|
def get_lastrowid(self):
|
|
return self._lastrowid
|
|
|
|
@property
|
|
def rowcount(self):
|
|
if self._rowcount is not None:
|
|
return self._rowcount
|
|
else:
|
|
return self.cursor.rowcount
|
|
|
|
def handle_dbapi_exception(self, e):
|
|
if self._enable_identity_insert:
|
|
try:
|
|
self.cursor.execute(
|
|
self._opt_encode(
|
|
"SET IDENTITY_INSERT %s OFF"
|
|
% self.identifier_preparer.format_table(
|
|
self.compiled.compile_state.dml_table
|
|
)
|
|
)
|
|
)
|
|
except Exception:
|
|
pass
|
|
|
|
def get_result_cursor_strategy(self, result):
|
|
if self._result_strategy:
|
|
return self._result_strategy
|
|
else:
|
|
return super(MSExecutionContext, self).get_result_cursor_strategy(
|
|
result
|
|
)
|
|
|
|
def fire_sequence(self, seq, type_):
|
|
return self._execute_scalar(
|
|
(
|
|
"SELECT NEXT VALUE FOR %s"
|
|
% self.identifier_preparer.format_sequence(seq)
|
|
),
|
|
type_,
|
|
)
|
|
|
|
def get_insert_default(self, column):
|
|
if (
|
|
isinstance(column, sa_schema.Column)
|
|
and column is column.table._autoincrement_column
|
|
and isinstance(column.default, sa_schema.Sequence)
|
|
and column.default.optional
|
|
):
|
|
return None
|
|
return super(MSExecutionContext, self).get_insert_default(column)
|
|
|
|
|
|
class MSSQLCompiler(compiler.SQLCompiler):
|
|
returning_precedes_values = True
|
|
|
|
extract_map = util.update_copy(
|
|
compiler.SQLCompiler.extract_map,
|
|
{
|
|
"doy": "dayofyear",
|
|
"dow": "weekday",
|
|
"milliseconds": "millisecond",
|
|
"microseconds": "microsecond",
|
|
},
|
|
)
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
self.tablealiases = {}
|
|
super(MSSQLCompiler, self).__init__(*args, **kwargs)
|
|
|
|
def _with_legacy_schema_aliasing(fn):
|
|
def decorate(self, *arg, **kw):
|
|
if self.dialect.legacy_schema_aliasing:
|
|
return fn(self, *arg, **kw)
|
|
else:
|
|
super_ = getattr(super(MSSQLCompiler, self), fn.__name__)
|
|
return super_(*arg, **kw)
|
|
|
|
return decorate
|
|
|
|
def visit_now_func(self, fn, **kw):
|
|
return "CURRENT_TIMESTAMP"
|
|
|
|
def visit_current_date_func(self, fn, **kw):
|
|
return "GETDATE()"
|
|
|
|
def visit_length_func(self, fn, **kw):
|
|
return "LEN%s" % self.function_argspec(fn, **kw)
|
|
|
|
def visit_char_length_func(self, fn, **kw):
|
|
return "LEN%s" % self.function_argspec(fn, **kw)
|
|
|
|
def visit_concat_op_binary(self, binary, operator, **kw):
|
|
return "%s + %s" % (
|
|
self.process(binary.left, **kw),
|
|
self.process(binary.right, **kw),
|
|
)
|
|
|
|
def visit_true(self, expr, **kw):
|
|
return "1"
|
|
|
|
def visit_false(self, expr, **kw):
|
|
return "0"
|
|
|
|
def visit_match_op_binary(self, binary, operator, **kw):
|
|
return "CONTAINS (%s, %s)" % (
|
|
self.process(binary.left, **kw),
|
|
self.process(binary.right, **kw),
|
|
)
|
|
|
|
def get_select_precolumns(self, select, **kw):
|
|
"""MS-SQL puts TOP, it's version of LIMIT here"""
|
|
|
|
s = super(MSSQLCompiler, self).get_select_precolumns(select, **kw)
|
|
|
|
if select._has_row_limiting_clause and self._use_top(select):
|
|
# ODBC drivers and possibly others
|
|
# don't support bind params in the SELECT clause on SQL Server.
|
|
# so have to use literal here.
|
|
kw["literal_execute"] = True
|
|
s += "TOP %s " % self.process(
|
|
self._get_limit_or_fetch(select), **kw
|
|
)
|
|
if select._fetch_clause is not None:
|
|
if select._fetch_clause_options["percent"]:
|
|
s += "PERCENT "
|
|
if select._fetch_clause_options["with_ties"]:
|
|
s += "WITH TIES "
|
|
|
|
return s
|
|
|
|
def get_from_hint_text(self, table, text):
|
|
return text
|
|
|
|
def get_crud_hint_text(self, table, text):
|
|
return text
|
|
|
|
def _get_limit_or_fetch(self, select):
|
|
if select._fetch_clause is None:
|
|
return select._limit_clause
|
|
else:
|
|
return select._fetch_clause
|
|
|
|
def _use_top(self, select):
|
|
return (select._offset_clause is None) and (
|
|
select._simple_int_clause(select._limit_clause)
|
|
or (
|
|
# limit can use TOP with is by itself. fetch only uses TOP
|
|
# when it needs to because of PERCENT and/or WITH TIES
|
|
select._simple_int_clause(select._fetch_clause)
|
|
and (
|
|
select._fetch_clause_options["percent"]
|
|
or select._fetch_clause_options["with_ties"]
|
|
)
|
|
)
|
|
)
|
|
|
|
def fetch_clause(self, cs, **kwargs):
|
|
return ""
|
|
|
|
def limit_clause(self, cs, **kwargs):
|
|
return ""
|
|
|
|
def _check_can_use_fetch_limit(self, select):
|
|
# to use ROW_NUMBER(), an ORDER BY is required.
|
|
# OFFSET are FETCH are options of the ORDER BY clause
|
|
if not select._order_by_clause.clauses:
|
|
raise exc.CompileError(
|
|
"MSSQL requires an order_by when "
|
|
"using an OFFSET or a non-simple "
|
|
"LIMIT clause"
|
|
)
|
|
|
|
if select._fetch_clause_options is not None and (
|
|
select._fetch_clause_options["percent"]
|
|
or select._fetch_clause_options["with_ties"]
|
|
):
|
|
raise exc.CompileError(
|
|
"MSSQL needs TOP to use PERCENT and/or WITH TIES. "
|
|
"Only simple fetch without offset can be used."
|
|
)
|
|
|
|
def _row_limit_clause(self, select, **kw):
|
|
"""MSSQL 2012 supports OFFSET/FETCH operators
|
|
Use it instead subquery with row_number
|
|
|
|
"""
|
|
|
|
if self.dialect._supports_offset_fetch and not self._use_top(select):
|
|
self._check_can_use_fetch_limit(select)
|
|
|
|
text = ""
|
|
|
|
if select._offset_clause is not None:
|
|
offset_str = self.process(select._offset_clause, **kw)
|
|
else:
|
|
offset_str = "0"
|
|
text += "\n OFFSET %s ROWS" % offset_str
|
|
|
|
limit = self._get_limit_or_fetch(select)
|
|
|
|
if limit is not None:
|
|
text += "\n FETCH FIRST %s ROWS ONLY" % self.process(
|
|
limit, **kw
|
|
)
|
|
return text
|
|
else:
|
|
return ""
|
|
|
|
def visit_try_cast(self, element, **kw):
|
|
return "TRY_CAST (%s AS %s)" % (
|
|
self.process(element.clause, **kw),
|
|
self.process(element.typeclause, **kw),
|
|
)
|
|
|
|
def translate_select_structure(self, select_stmt, **kwargs):
|
|
"""Look for ``LIMIT`` and OFFSET in a select statement, and if
|
|
so tries to wrap it in a subquery with ``row_number()`` criterion.
|
|
MSSQL 2012 and above are excluded
|
|
|
|
"""
|
|
select = select_stmt
|
|
|
|
if (
|
|
select._has_row_limiting_clause
|
|
and not self.dialect._supports_offset_fetch
|
|
and not self._use_top(select)
|
|
and not getattr(select, "_mssql_visit", None)
|
|
):
|
|
self._check_can_use_fetch_limit(select)
|
|
|
|
_order_by_clauses = [
|
|
sql_util.unwrap_label_reference(elem)
|
|
for elem in select._order_by_clause.clauses
|
|
]
|
|
|
|
limit_clause = self._get_limit_or_fetch(select)
|
|
offset_clause = select._offset_clause
|
|
|
|
select = select._generate()
|
|
select._mssql_visit = True
|
|
select = (
|
|
select.add_columns(
|
|
sql.func.ROW_NUMBER()
|
|
.over(order_by=_order_by_clauses)
|
|
.label("mssql_rn")
|
|
)
|
|
.order_by(None)
|
|
.alias()
|
|
)
|
|
|
|
mssql_rn = sql.column("mssql_rn")
|
|
limitselect = sql.select(
|
|
*[c for c in select.c if c.key != "mssql_rn"]
|
|
)
|
|
if offset_clause is not None:
|
|
limitselect = limitselect.where(mssql_rn > offset_clause)
|
|
if limit_clause is not None:
|
|
limitselect = limitselect.where(
|
|
mssql_rn <= (limit_clause + offset_clause)
|
|
)
|
|
else:
|
|
limitselect = limitselect.where(mssql_rn <= (limit_clause))
|
|
return limitselect
|
|
else:
|
|
return select
|
|
|
|
@_with_legacy_schema_aliasing
|
|
def visit_table(self, table, mssql_aliased=False, iscrud=False, **kwargs):
|
|
if mssql_aliased is table or iscrud:
|
|
return super(MSSQLCompiler, self).visit_table(table, **kwargs)
|
|
|
|
# alias schema-qualified tables
|
|
alias = self._schema_aliased_table(table)
|
|
if alias is not None:
|
|
return self.process(alias, mssql_aliased=table, **kwargs)
|
|
else:
|
|
return super(MSSQLCompiler, self).visit_table(table, **kwargs)
|
|
|
|
@_with_legacy_schema_aliasing
|
|
def visit_alias(self, alias, **kw):
|
|
# translate for schema-qualified table aliases
|
|
kw["mssql_aliased"] = alias.element
|
|
return super(MSSQLCompiler, self).visit_alias(alias, **kw)
|
|
|
|
@_with_legacy_schema_aliasing
|
|
def visit_column(self, column, add_to_result_map=None, **kw):
|
|
if (
|
|
column.table is not None
|
|
and (not self.isupdate and not self.isdelete)
|
|
or self.is_subquery()
|
|
):
|
|
# translate for schema-qualified table aliases
|
|
t = self._schema_aliased_table(column.table)
|
|
if t is not None:
|
|
converted = elements._corresponding_column_or_error(t, column)
|
|
if add_to_result_map is not None:
|
|
add_to_result_map(
|
|
column.name,
|
|
column.name,
|
|
(column, column.name, column.key),
|
|
column.type,
|
|
)
|
|
|
|
return super(MSSQLCompiler, self).visit_column(converted, **kw)
|
|
|
|
return super(MSSQLCompiler, self).visit_column(
|
|
column, add_to_result_map=add_to_result_map, **kw
|
|
)
|
|
|
|
def _schema_aliased_table(self, table):
|
|
if getattr(table, "schema", None) is not None:
|
|
if table not in self.tablealiases:
|
|
self.tablealiases[table] = table.alias()
|
|
return self.tablealiases[table]
|
|
else:
|
|
return None
|
|
|
|
def visit_extract(self, extract, **kw):
|
|
field = self.extract_map.get(extract.field, extract.field)
|
|
return "DATEPART(%s, %s)" % (field, self.process(extract.expr, **kw))
|
|
|
|
def visit_savepoint(self, savepoint_stmt):
|
|
return "SAVE TRANSACTION %s" % self.preparer.format_savepoint(
|
|
savepoint_stmt
|
|
)
|
|
|
|
def visit_rollback_to_savepoint(self, savepoint_stmt):
|
|
return "ROLLBACK TRANSACTION %s" % self.preparer.format_savepoint(
|
|
savepoint_stmt
|
|
)
|
|
|
|
def visit_binary(self, binary, **kwargs):
|
|
"""Move bind parameters to the right-hand side of an operator, where
|
|
possible.
|
|
|
|
"""
|
|
if (
|
|
isinstance(binary.left, expression.BindParameter)
|
|
and binary.operator == operator.eq
|
|
and not isinstance(binary.right, expression.BindParameter)
|
|
):
|
|
return self.process(
|
|
expression.BinaryExpression(
|
|
binary.right, binary.left, binary.operator
|
|
),
|
|
**kwargs
|
|
)
|
|
return super(MSSQLCompiler, self).visit_binary(binary, **kwargs)
|
|
|
|
def returning_clause(self, stmt, returning_cols):
|
|
# SQL server returning clause requires that the columns refer to
|
|
# the virtual table names "inserted" or "deleted". Here, we make
|
|
# a simple alias of our table with that name, and then adapt the
|
|
# columns we have from the list of RETURNING columns to that new name
|
|
# so that they render as "inserted.<colname>" / "deleted.<colname>".
|
|
|
|
if self.isinsert or self.isupdate:
|
|
target = stmt.table.alias("inserted")
|
|
else:
|
|
target = stmt.table.alias("deleted")
|
|
|
|
adapter = sql_util.ClauseAdapter(target)
|
|
|
|
# adapter.traverse() takes a column from our target table and returns
|
|
# the one that is linked to the "inserted" / "deleted" tables. So in
|
|
# order to retrieve these values back from the result (e.g. like
|
|
# row[column]), tell the compiler to also add the original unadapted
|
|
# column to the result map. Before #4877, these were (unknowingly)
|
|
# falling back using string name matching in the result set which
|
|
# necessarily used an expensive KeyError in order to match.
|
|
|
|
columns = [
|
|
self._label_select_column(
|
|
None,
|
|
adapter.traverse(c),
|
|
True,
|
|
False,
|
|
{"result_map_targets": (c,)},
|
|
)
|
|
for c in expression._select_iterables(returning_cols)
|
|
]
|
|
|
|
return "OUTPUT " + ", ".join(columns)
|
|
|
|
def get_cte_preamble(self, recursive):
|
|
# SQL Server finds it too inconvenient to accept
|
|
# an entirely optional, SQL standard specified,
|
|
# "RECURSIVE" word with their "WITH",
|
|
# so here we go
|
|
return "WITH"
|
|
|
|
def label_select_column(self, select, column, asfrom):
|
|
if isinstance(column, expression.Function):
|
|
return column.label(None)
|
|
else:
|
|
return super(MSSQLCompiler, self).label_select_column(
|
|
select, column, asfrom
|
|
)
|
|
|
|
def for_update_clause(self, select, **kw):
|
|
# "FOR UPDATE" is only allowed on "DECLARE CURSOR" which
|
|
# SQLAlchemy doesn't use
|
|
return ""
|
|
|
|
def order_by_clause(self, select, **kw):
|
|
# MSSQL only allows ORDER BY in subqueries if there is a LIMIT
|
|
if (
|
|
self.is_subquery()
|
|
and not select._limit
|
|
and (
|
|
select._offset is None
|
|
or not self.dialect._supports_offset_fetch
|
|
)
|
|
):
|
|
# avoid processing the order by clause if we won't end up
|
|
# using it, because we don't want all the bind params tacked
|
|
# onto the positional list if that is what the dbapi requires
|
|
return ""
|
|
|
|
order_by = self.process(select._order_by_clause, **kw)
|
|
|
|
if order_by:
|
|
return " ORDER BY " + order_by
|
|
else:
|
|
return ""
|
|
|
|
def update_from_clause(
|
|
self, update_stmt, from_table, extra_froms, from_hints, **kw
|
|
):
|
|
"""Render the UPDATE..FROM clause specific to MSSQL.
|
|
|
|
In MSSQL, if the UPDATE statement involves an alias of the table to
|
|
be updated, then the table itself must be added to the FROM list as
|
|
well. Otherwise, it is optional. Here, we add it regardless.
|
|
|
|
"""
|
|
return "FROM " + ", ".join(
|
|
t._compiler_dispatch(self, asfrom=True, fromhints=from_hints, **kw)
|
|
for t in [from_table] + extra_froms
|
|
)
|
|
|
|
def delete_table_clause(self, delete_stmt, from_table, extra_froms):
|
|
"""If we have extra froms make sure we render any alias as hint."""
|
|
ashint = False
|
|
if extra_froms:
|
|
ashint = True
|
|
return from_table._compiler_dispatch(
|
|
self, asfrom=True, iscrud=True, ashint=ashint
|
|
)
|
|
|
|
def delete_extra_from_clause(
|
|
self, delete_stmt, from_table, extra_froms, from_hints, **kw
|
|
):
|
|
"""Render the DELETE .. FROM clause specific to MSSQL.
|
|
|
|
Yes, it has the FROM keyword twice.
|
|
|
|
"""
|
|
return "FROM " + ", ".join(
|
|
t._compiler_dispatch(self, asfrom=True, fromhints=from_hints, **kw)
|
|
for t in [from_table] + extra_froms
|
|
)
|
|
|
|
def visit_empty_set_expr(self, type_):
|
|
return "SELECT 1 WHERE 1!=1"
|
|
|
|
def visit_is_distinct_from_binary(self, binary, operator, **kw):
|
|
return "NOT EXISTS (SELECT %s INTERSECT SELECT %s)" % (
|
|
self.process(binary.left),
|
|
self.process(binary.right),
|
|
)
|
|
|
|
def visit_is_not_distinct_from_binary(self, binary, operator, **kw):
|
|
return "EXISTS (SELECT %s INTERSECT SELECT %s)" % (
|
|
self.process(binary.left),
|
|
self.process(binary.right),
|
|
)
|
|
|
|
def _render_json_extract_from_binary(self, binary, operator, **kw):
|
|
# note we are intentionally calling upon the process() calls in the
|
|
# order in which they appear in the SQL String as this is used
|
|
# by positional parameter rendering
|
|
|
|
if binary.type._type_affinity is sqltypes.JSON:
|
|
return "JSON_QUERY(%s, %s)" % (
|
|
self.process(binary.left, **kw),
|
|
self.process(binary.right, **kw),
|
|
)
|
|
|
|
# as with other dialects, start with an explicit test for NULL
|
|
case_expression = "CASE JSON_VALUE(%s, %s) WHEN NULL THEN NULL" % (
|
|
self.process(binary.left, **kw),
|
|
self.process(binary.right, **kw),
|
|
)
|
|
|
|
if binary.type._type_affinity is sqltypes.Integer:
|
|
type_expression = "ELSE CAST(JSON_VALUE(%s, %s) AS INTEGER)" % (
|
|
self.process(binary.left, **kw),
|
|
self.process(binary.right, **kw),
|
|
)
|
|
elif binary.type._type_affinity is sqltypes.Numeric:
|
|
type_expression = "ELSE CAST(JSON_VALUE(%s, %s) AS %s)" % (
|
|
self.process(binary.left, **kw),
|
|
self.process(binary.right, **kw),
|
|
"FLOAT"
|
|
if isinstance(binary.type, sqltypes.Float)
|
|
else "NUMERIC(%s, %s)"
|
|
% (binary.type.precision, binary.type.scale),
|
|
)
|
|
elif binary.type._type_affinity is sqltypes.Boolean:
|
|
# the NULL handling is particularly weird with boolean, so
|
|
# explicitly return numeric (BIT) constants
|
|
type_expression = (
|
|
"WHEN 'true' THEN 1 WHEN 'false' THEN 0 ELSE NULL"
|
|
)
|
|
elif binary.type._type_affinity is sqltypes.String:
|
|
# TODO: does this comment (from mysql) apply to here, too?
|
|
# this fails with a JSON value that's a four byte unicode
|
|
# string. SQLite has the same problem at the moment
|
|
type_expression = "ELSE JSON_VALUE(%s, %s)" % (
|
|
self.process(binary.left, **kw),
|
|
self.process(binary.right, **kw),
|
|
)
|
|
else:
|
|
# other affinity....this is not expected right now
|
|
type_expression = "ELSE JSON_QUERY(%s, %s)" % (
|
|
self.process(binary.left, **kw),
|
|
self.process(binary.right, **kw),
|
|
)
|
|
|
|
return case_expression + " " + type_expression + " END"
|
|
|
|
def visit_json_getitem_op_binary(self, binary, operator, **kw):
|
|
return self._render_json_extract_from_binary(binary, operator, **kw)
|
|
|
|
def visit_json_path_getitem_op_binary(self, binary, operator, **kw):
|
|
return self._render_json_extract_from_binary(binary, operator, **kw)
|
|
|
|
def visit_sequence(self, seq, **kw):
|
|
return "NEXT VALUE FOR %s" % self.preparer.format_sequence(seq)
|
|
|
|
|
|
class MSSQLStrictCompiler(MSSQLCompiler):
|
|
|
|
"""A subclass of MSSQLCompiler which disables the usage of bind
|
|
parameters where not allowed natively by MS-SQL.
|
|
|
|
A dialect may use this compiler on a platform where native
|
|
binds are used.
|
|
|
|
"""
|
|
|
|
ansi_bind_rules = True
|
|
|
|
def visit_in_op_binary(self, binary, operator, **kw):
|
|
kw["literal_execute"] = True
|
|
return "%s IN %s" % (
|
|
self.process(binary.left, **kw),
|
|
self.process(binary.right, **kw),
|
|
)
|
|
|
|
def visit_not_in_op_binary(self, binary, operator, **kw):
|
|
kw["literal_execute"] = True
|
|
return "%s NOT IN %s" % (
|
|
self.process(binary.left, **kw),
|
|
self.process(binary.right, **kw),
|
|
)
|
|
|
|
def render_literal_value(self, value, type_):
|
|
"""
|
|
For date and datetime values, convert to a string
|
|
format acceptable to MSSQL. That seems to be the
|
|
so-called ODBC canonical date format which looks
|
|
like this:
|
|
|
|
yyyy-mm-dd hh:mi:ss.mmm(24h)
|
|
|
|
For other data types, call the base class implementation.
|
|
"""
|
|
# datetime and date are both subclasses of datetime.date
|
|
if issubclass(type(value), datetime.date):
|
|
# SQL Server wants single quotes around the date string.
|
|
return "'" + str(value) + "'"
|
|
else:
|
|
return super(MSSQLStrictCompiler, self).render_literal_value(
|
|
value, type_
|
|
)
|
|
|
|
|
|
class MSDDLCompiler(compiler.DDLCompiler):
|
|
def get_column_specification(self, column, **kwargs):
|
|
colspec = self.preparer.format_column(column)
|
|
|
|
# type is not accepted in a computed column
|
|
if column.computed is not None:
|
|
colspec += " " + self.process(column.computed)
|
|
else:
|
|
colspec += " " + self.dialect.type_compiler.process(
|
|
column.type, type_expression=column
|
|
)
|
|
|
|
if column.nullable is not None:
|
|
if (
|
|
not column.nullable
|
|
or column.primary_key
|
|
or isinstance(column.default, sa_schema.Sequence)
|
|
or column.autoincrement is True
|
|
or column.identity
|
|
):
|
|
colspec += " NOT NULL"
|
|
elif column.computed is None:
|
|
# don't specify "NULL" for computed columns
|
|
colspec += " NULL"
|
|
|
|
if column.table is None:
|
|
raise exc.CompileError(
|
|
"mssql requires Table-bound columns "
|
|
"in order to generate DDL"
|
|
)
|
|
|
|
d_opt = column.dialect_options["mssql"]
|
|
start = d_opt["identity_start"]
|
|
increment = d_opt["identity_increment"]
|
|
if start is not None or increment is not None:
|
|
if column.identity:
|
|
raise exc.CompileError(
|
|
"Cannot specify options 'mssql_identity_start' and/or "
|
|
"'mssql_identity_increment' while also using the "
|
|
"'Identity' construct."
|
|
)
|
|
util.warn_deprecated(
|
|
"The dialect options 'mssql_identity_start' and "
|
|
"'mssql_identity_increment' are deprecated. "
|
|
"Use the 'Identity' object instead.",
|
|
"1.4",
|
|
)
|
|
|
|
if column.identity:
|
|
colspec += self.process(column.identity, **kwargs)
|
|
elif (
|
|
column is column.table._autoincrement_column
|
|
or column.autoincrement is True
|
|
) and (
|
|
not isinstance(column.default, Sequence) or column.default.optional
|
|
):
|
|
colspec += self.process(Identity(start=start, increment=increment))
|
|
else:
|
|
default = self.get_column_default_string(column)
|
|
if default is not None:
|
|
colspec += " DEFAULT " + default
|
|
|
|
return colspec
|
|
|
|
def visit_create_index(self, create, include_schema=False):
|
|
index = create.element
|
|
self._verify_index_table(index)
|
|
preparer = self.preparer
|
|
text = "CREATE "
|
|
if index.unique:
|
|
text += "UNIQUE "
|
|
|
|
# handle clustering option
|
|
clustered = index.dialect_options["mssql"]["clustered"]
|
|
if clustered is not None:
|
|
if clustered:
|
|
text += "CLUSTERED "
|
|
else:
|
|
text += "NONCLUSTERED "
|
|
|
|
text += "INDEX %s ON %s (%s)" % (
|
|
self._prepared_index_name(index, include_schema=include_schema),
|
|
preparer.format_table(index.table),
|
|
", ".join(
|
|
self.sql_compiler.process(
|
|
expr, include_table=False, literal_binds=True
|
|
)
|
|
for expr in index.expressions
|
|
),
|
|
)
|
|
|
|
# handle other included columns
|
|
if index.dialect_options["mssql"]["include"]:
|
|
inclusions = [
|
|
index.table.c[col]
|
|
if isinstance(col, util.string_types)
|
|
else col
|
|
for col in index.dialect_options["mssql"]["include"]
|
|
]
|
|
|
|
text += " INCLUDE (%s)" % ", ".join(
|
|
[preparer.quote(c.name) for c in inclusions]
|
|
)
|
|
|
|
whereclause = index.dialect_options["mssql"]["where"]
|
|
|
|
if whereclause is not None:
|
|
whereclause = coercions.expect(
|
|
roles.DDLExpressionRole, whereclause
|
|
)
|
|
|
|
where_compiled = self.sql_compiler.process(
|
|
whereclause, include_table=False, literal_binds=True
|
|
)
|
|
text += " WHERE " + where_compiled
|
|
|
|
return text
|
|
|
|
def visit_drop_index(self, drop):
|
|
return "\nDROP INDEX %s ON %s" % (
|
|
self._prepared_index_name(drop.element, include_schema=False),
|
|
self.preparer.format_table(drop.element.table),
|
|
)
|
|
|
|
def visit_primary_key_constraint(self, constraint):
|
|
if len(constraint) == 0:
|
|
return ""
|
|
text = ""
|
|
if constraint.name is not None:
|
|
text += "CONSTRAINT %s " % self.preparer.format_constraint(
|
|
constraint
|
|
)
|
|
text += "PRIMARY KEY "
|
|
|
|
clustered = constraint.dialect_options["mssql"]["clustered"]
|
|
if clustered is not None:
|
|
if clustered:
|
|
text += "CLUSTERED "
|
|
else:
|
|
text += "NONCLUSTERED "
|
|
|
|
text += "(%s)" % ", ".join(
|
|
self.preparer.quote(c.name) for c in constraint
|
|
)
|
|
text += self.define_constraint_deferrability(constraint)
|
|
return text
|
|
|
|
def visit_unique_constraint(self, constraint):
|
|
if len(constraint) == 0:
|
|
return ""
|
|
text = ""
|
|
if constraint.name is not None:
|
|
formatted_name = self.preparer.format_constraint(constraint)
|
|
if formatted_name is not None:
|
|
text += "CONSTRAINT %s " % formatted_name
|
|
text += "UNIQUE "
|
|
|
|
clustered = constraint.dialect_options["mssql"]["clustered"]
|
|
if clustered is not None:
|
|
if clustered:
|
|
text += "CLUSTERED "
|
|
else:
|
|
text += "NONCLUSTERED "
|
|
|
|
text += "(%s)" % ", ".join(
|
|
self.preparer.quote(c.name) for c in constraint
|
|
)
|
|
text += self.define_constraint_deferrability(constraint)
|
|
return text
|
|
|
|
def visit_computed_column(self, generated):
|
|
text = "AS (%s)" % self.sql_compiler.process(
|
|
generated.sqltext, include_table=False, literal_binds=True
|
|
)
|
|
# explicitly check for True|False since None means server default
|
|
if generated.persisted is True:
|
|
text += " PERSISTED"
|
|
return text
|
|
|
|
def visit_create_sequence(self, create, **kw):
|
|
prefix = None
|
|
if create.element.data_type is not None:
|
|
data_type = create.element.data_type
|
|
prefix = " AS %s" % self.type_compiler.process(data_type)
|
|
return super(MSDDLCompiler, self).visit_create_sequence(
|
|
create, prefix=prefix, **kw
|
|
)
|
|
|
|
def visit_identity_column(self, identity, **kw):
|
|
text = " IDENTITY"
|
|
if identity.start is not None or identity.increment is not None:
|
|
start = 1 if identity.start is None else identity.start
|
|
increment = 1 if identity.increment is None else identity.increment
|
|
text += "(%s,%s)" % (start, increment)
|
|
return text
|
|
|
|
|
|
class MSIdentifierPreparer(compiler.IdentifierPreparer):
|
|
reserved_words = RESERVED_WORDS
|
|
|
|
def __init__(self, dialect):
|
|
super(MSIdentifierPreparer, self).__init__(
|
|
dialect,
|
|
initial_quote="[",
|
|
final_quote="]",
|
|
quote_case_sensitive_collations=False,
|
|
)
|
|
|
|
def _escape_identifier(self, value):
|
|
return value.replace("]", "]]")
|
|
|
|
def _unescape_identifier(self, value):
|
|
return value.replace("]]", "]")
|
|
|
|
def quote_schema(self, schema, force=None):
|
|
"""Prepare a quoted table and schema name."""
|
|
|
|
# need to re-implement the deprecation warning entirely
|
|
if force is not None:
|
|
# not using the util.deprecated_params() decorator in this
|
|
# case because of the additional function call overhead on this
|
|
# very performance-critical spot.
|
|
util.warn_deprecated(
|
|
"The IdentifierPreparer.quote_schema.force parameter is "
|
|
"deprecated and will be removed in a future release. This "
|
|
"flag has no effect on the behavior of the "
|
|
"IdentifierPreparer.quote method; please refer to "
|
|
"quoted_name().",
|
|
version="1.3",
|
|
)
|
|
|
|
dbname, owner = _schema_elements(schema)
|
|
if dbname:
|
|
result = "%s.%s" % (self.quote(dbname), self.quote(owner))
|
|
elif owner:
|
|
result = self.quote(owner)
|
|
else:
|
|
result = ""
|
|
return result
|
|
|
|
|
|
def _db_plus_owner_listing(fn):
|
|
def wrap(dialect, connection, schema=None, **kw):
|
|
dbname, owner = _owner_plus_db(dialect, schema)
|
|
return _switch_db(
|
|
dbname,
|
|
connection,
|
|
fn,
|
|
dialect,
|
|
connection,
|
|
dbname,
|
|
owner,
|
|
schema,
|
|
**kw
|
|
)
|
|
|
|
return update_wrapper(wrap, fn)
|
|
|
|
|
|
def _db_plus_owner(fn):
|
|
def wrap(dialect, connection, tablename, schema=None, **kw):
|
|
dbname, owner = _owner_plus_db(dialect, schema)
|
|
return _switch_db(
|
|
dbname,
|
|
connection,
|
|
fn,
|
|
dialect,
|
|
connection,
|
|
tablename,
|
|
dbname,
|
|
owner,
|
|
schema,
|
|
**kw
|
|
)
|
|
|
|
return update_wrapper(wrap, fn)
|
|
|
|
|
|
def _switch_db(dbname, connection, fn, *arg, **kw):
|
|
if dbname:
|
|
current_db = connection.exec_driver_sql("select db_name()").scalar()
|
|
if current_db != dbname:
|
|
connection.exec_driver_sql(
|
|
"use %s" % connection.dialect.identifier_preparer.quote(dbname)
|
|
)
|
|
try:
|
|
return fn(*arg, **kw)
|
|
finally:
|
|
if dbname and current_db != dbname:
|
|
connection.exec_driver_sql(
|
|
"use %s"
|
|
% connection.dialect.identifier_preparer.quote(current_db)
|
|
)
|
|
|
|
|
|
def _owner_plus_db(dialect, schema):
|
|
if not schema:
|
|
return None, dialect.default_schema_name
|
|
elif "." in schema:
|
|
return _schema_elements(schema)
|
|
else:
|
|
return None, schema
|
|
|
|
|
|
_memoized_schema = util.LRUCache()
|
|
|
|
|
|
def _schema_elements(schema):
|
|
if isinstance(schema, quoted_name) and schema.quote:
|
|
return None, schema
|
|
|
|
if schema in _memoized_schema:
|
|
return _memoized_schema[schema]
|
|
|
|
# tests for this function are in:
|
|
# test/dialect/mssql/test_reflection.py ->
|
|
# OwnerPlusDBTest.test_owner_database_pairs
|
|
# test/dialect/mssql/test_compiler.py -> test_force_schema_*
|
|
# test/dialect/mssql/test_compiler.py -> test_schema_many_tokens_*
|
|
#
|
|
|
|
push = []
|
|
symbol = ""
|
|
bracket = False
|
|
has_brackets = False
|
|
for token in re.split(r"(\[|\]|\.)", schema):
|
|
if not token:
|
|
continue
|
|
if token == "[":
|
|
bracket = True
|
|
has_brackets = True
|
|
elif token == "]":
|
|
bracket = False
|
|
elif not bracket and token == ".":
|
|
if has_brackets:
|
|
push.append("[%s]" % symbol)
|
|
else:
|
|
push.append(symbol)
|
|
symbol = ""
|
|
has_brackets = False
|
|
else:
|
|
symbol += token
|
|
if symbol:
|
|
push.append(symbol)
|
|
if len(push) > 1:
|
|
dbname, owner = ".".join(push[0:-1]), push[-1]
|
|
|
|
# test for internal brackets
|
|
if re.match(r".*\].*\[.*", dbname[1:-1]):
|
|
dbname = quoted_name(dbname, quote=False)
|
|
else:
|
|
dbname = dbname.lstrip("[").rstrip("]")
|
|
|
|
elif len(push):
|
|
dbname, owner = None, push[0]
|
|
else:
|
|
dbname, owner = None, None
|
|
|
|
_memoized_schema[schema] = dbname, owner
|
|
return dbname, owner
|
|
|
|
|
|
class MSDialect(default.DefaultDialect):
|
|
# will assume it's at least mssql2005
|
|
name = "mssql"
|
|
supports_statement_cache = True
|
|
supports_default_values = True
|
|
supports_empty_insert = False
|
|
execution_ctx_cls = MSExecutionContext
|
|
use_scope_identity = True
|
|
max_identifier_length = 128
|
|
schema_name = "dbo"
|
|
|
|
implicit_returning = True
|
|
full_returning = True
|
|
|
|
colspecs = {
|
|
sqltypes.DateTime: _MSDateTime,
|
|
sqltypes.Date: _MSDate,
|
|
sqltypes.JSON: JSON,
|
|
sqltypes.JSON.JSONIndexType: JSONIndexType,
|
|
sqltypes.JSON.JSONPathType: JSONPathType,
|
|
sqltypes.Time: TIME,
|
|
sqltypes.Unicode: _MSUnicode,
|
|
sqltypes.UnicodeText: _MSUnicodeText,
|
|
}
|
|
|
|
engine_config_types = default.DefaultDialect.engine_config_types.union(
|
|
{"legacy_schema_aliasing": util.asbool}
|
|
)
|
|
|
|
ischema_names = ischema_names
|
|
|
|
supports_sequences = True
|
|
sequences_optional = True
|
|
# T-SQL's actual default is -9223372036854775808
|
|
default_sequence_base = 1
|
|
|
|
supports_native_boolean = False
|
|
non_native_boolean_check_constraint = False
|
|
supports_unicode_binds = True
|
|
postfetch_lastrowid = True
|
|
_supports_offset_fetch = False
|
|
_supports_nvarchar_max = False
|
|
|
|
legacy_schema_aliasing = False
|
|
|
|
server_version_info = ()
|
|
|
|
statement_compiler = MSSQLCompiler
|
|
ddl_compiler = MSDDLCompiler
|
|
type_compiler = MSTypeCompiler
|
|
preparer = MSIdentifierPreparer
|
|
|
|
construct_arguments = [
|
|
(sa_schema.PrimaryKeyConstraint, {"clustered": None}),
|
|
(sa_schema.UniqueConstraint, {"clustered": None}),
|
|
(sa_schema.Index, {"clustered": None, "include": None, "where": None}),
|
|
(
|
|
sa_schema.Column,
|
|
{"identity_start": None, "identity_increment": None},
|
|
),
|
|
]
|
|
|
|
def __init__(
|
|
self,
|
|
query_timeout=None,
|
|
use_scope_identity=True,
|
|
schema_name="dbo",
|
|
isolation_level=None,
|
|
deprecate_large_types=None,
|
|
json_serializer=None,
|
|
json_deserializer=None,
|
|
legacy_schema_aliasing=None,
|
|
**opts
|
|
):
|
|
self.query_timeout = int(query_timeout or 0)
|
|
self.schema_name = schema_name
|
|
|
|
self.use_scope_identity = use_scope_identity
|
|
self.deprecate_large_types = deprecate_large_types
|
|
|
|
if legacy_schema_aliasing is not None:
|
|
util.warn_deprecated(
|
|
"The legacy_schema_aliasing parameter is "
|
|
"deprecated and will be removed in a future release.",
|
|
"1.4",
|
|
)
|
|
self.legacy_schema_aliasing = legacy_schema_aliasing
|
|
|
|
super(MSDialect, self).__init__(**opts)
|
|
|
|
self.isolation_level = isolation_level
|
|
self._json_serializer = json_serializer
|
|
self._json_deserializer = json_deserializer
|
|
|
|
def do_savepoint(self, connection, name):
|
|
# give the DBAPI a push
|
|
connection.exec_driver_sql("IF @@TRANCOUNT = 0 BEGIN TRANSACTION")
|
|
super(MSDialect, self).do_savepoint(connection, name)
|
|
|
|
def do_release_savepoint(self, connection, name):
|
|
# SQL Server does not support RELEASE SAVEPOINT
|
|
pass
|
|
|
|
_isolation_lookup = set(
|
|
[
|
|
"SERIALIZABLE",
|
|
"READ UNCOMMITTED",
|
|
"READ COMMITTED",
|
|
"REPEATABLE READ",
|
|
"SNAPSHOT",
|
|
]
|
|
)
|
|
|
|
def set_isolation_level(self, connection, level):
|
|
level = level.replace("_", " ")
|
|
if level not in self._isolation_lookup:
|
|
raise exc.ArgumentError(
|
|
"Invalid value '%s' for isolation_level. "
|
|
"Valid isolation levels for %s are %s"
|
|
% (level, self.name, ", ".join(self._isolation_lookup))
|
|
)
|
|
cursor = connection.cursor()
|
|
cursor.execute("SET TRANSACTION ISOLATION LEVEL %s" % level)
|
|
cursor.close()
|
|
if level == "SNAPSHOT":
|
|
connection.commit()
|
|
|
|
def get_isolation_level(self, connection):
|
|
last_error = None
|
|
|
|
views = ("sys.dm_exec_sessions", "sys.dm_pdw_nodes_exec_sessions")
|
|
for view in views:
|
|
cursor = connection.cursor()
|
|
try:
|
|
cursor.execute(
|
|
"""
|
|
SELECT CASE transaction_isolation_level
|
|
WHEN 0 THEN NULL
|
|
WHEN 1 THEN 'READ UNCOMMITTED'
|
|
WHEN 2 THEN 'READ COMMITTED'
|
|
WHEN 3 THEN 'REPEATABLE READ'
|
|
WHEN 4 THEN 'SERIALIZABLE'
|
|
WHEN 5 THEN 'SNAPSHOT' END AS TRANSACTION_ISOLATION_LEVEL
|
|
FROM %s
|
|
where session_id = @@SPID
|
|
"""
|
|
% view
|
|
)
|
|
val = cursor.fetchone()[0]
|
|
except self.dbapi.Error as err:
|
|
# Python3 scoping rules
|
|
last_error = err
|
|
continue
|
|
else:
|
|
return val.upper()
|
|
finally:
|
|
cursor.close()
|
|
else:
|
|
# note that the NotImplementedError is caught by
|
|
# DefaultDialect, so the warning here is all that displays
|
|
util.warn(
|
|
"Could not fetch transaction isolation level, "
|
|
"tried views: %s; final error was: %s" % (views, last_error)
|
|
)
|
|
raise NotImplementedError(
|
|
"Can't fetch isolation level on this particular "
|
|
"SQL Server version. tried views: %s; final error was: %s"
|
|
% (views, last_error)
|
|
)
|
|
|
|
def initialize(self, connection):
|
|
super(MSDialect, self).initialize(connection)
|
|
self._setup_version_attributes()
|
|
self._setup_supports_nvarchar_max(connection)
|
|
|
|
def on_connect(self):
|
|
if self.isolation_level is not None:
|
|
|
|
def connect(conn):
|
|
self.set_isolation_level(conn, self.isolation_level)
|
|
|
|
return connect
|
|
else:
|
|
return None
|
|
|
|
def _setup_version_attributes(self):
|
|
if self.server_version_info[0] not in list(range(8, 17)):
|
|
util.warn(
|
|
"Unrecognized server version info '%s'. Some SQL Server "
|
|
"features may not function properly."
|
|
% ".".join(str(x) for x in self.server_version_info)
|
|
)
|
|
|
|
if self.server_version_info >= MS_2008_VERSION:
|
|
self.supports_multivalues_insert = True
|
|
if self.deprecate_large_types is None:
|
|
self.deprecate_large_types = (
|
|
self.server_version_info >= MS_2012_VERSION
|
|
)
|
|
|
|
self._supports_offset_fetch = (
|
|
self.server_version_info and self.server_version_info[0] >= 11
|
|
)
|
|
|
|
def _setup_supports_nvarchar_max(self, connection):
|
|
try:
|
|
connection.scalar(
|
|
sql.text("SELECT CAST('test max support' AS NVARCHAR(max))")
|
|
)
|
|
except exc.DBAPIError:
|
|
self._supports_nvarchar_max = False
|
|
else:
|
|
self._supports_nvarchar_max = True
|
|
|
|
def _get_default_schema_name(self, connection):
|
|
query = sql.text("SELECT schema_name()")
|
|
default_schema_name = connection.scalar(query)
|
|
if default_schema_name is not None:
|
|
# guard against the case where the default_schema_name is being
|
|
# fed back into a table reflection function.
|
|
return quoted_name(default_schema_name, quote=True)
|
|
else:
|
|
return self.schema_name
|
|
|
|
@_db_plus_owner
|
|
def has_table(self, connection, tablename, dbname, owner, schema):
|
|
self._ensure_has_table_connection(connection)
|
|
if tablename.startswith("#"): # temporary table
|
|
tables = ischema.mssql_temp_table_columns
|
|
|
|
s = sql.select(tables.c.table_name).where(
|
|
tables.c.table_name.like(
|
|
self._temp_table_name_like_pattern(tablename)
|
|
)
|
|
)
|
|
|
|
result = connection.execute(s.limit(1))
|
|
return result.scalar() is not None
|
|
else:
|
|
tables = ischema.tables
|
|
|
|
s = sql.select(tables.c.table_name).where(
|
|
sql.and_(
|
|
tables.c.table_type == "BASE TABLE",
|
|
tables.c.table_name == tablename,
|
|
)
|
|
)
|
|
|
|
if owner:
|
|
s = s.where(tables.c.table_schema == owner)
|
|
|
|
c = connection.execute(s)
|
|
|
|
return c.first() is not None
|
|
|
|
@_db_plus_owner
|
|
def has_sequence(self, connection, sequencename, dbname, owner, schema):
|
|
sequences = ischema.sequences
|
|
|
|
s = sql.select(sequences.c.sequence_name).where(
|
|
sequences.c.sequence_name == sequencename
|
|
)
|
|
|
|
if owner:
|
|
s = s.where(sequences.c.sequence_schema == owner)
|
|
|
|
c = connection.execute(s)
|
|
|
|
return c.first() is not None
|
|
|
|
@reflection.cache
|
|
@_db_plus_owner_listing
|
|
def get_sequence_names(self, connection, dbname, owner, schema, **kw):
|
|
sequences = ischema.sequences
|
|
|
|
s = sql.select(sequences.c.sequence_name)
|
|
if owner:
|
|
s = s.where(sequences.c.sequence_schema == owner)
|
|
|
|
c = connection.execute(s)
|
|
|
|
return [row[0] for row in c]
|
|
|
|
@reflection.cache
|
|
def get_schema_names(self, connection, **kw):
|
|
s = sql.select(ischema.schemata.c.schema_name).order_by(
|
|
ischema.schemata.c.schema_name
|
|
)
|
|
schema_names = [r[0] for r in connection.execute(s)]
|
|
return schema_names
|
|
|
|
@reflection.cache
|
|
@_db_plus_owner_listing
|
|
def get_table_names(self, connection, dbname, owner, schema, **kw):
|
|
tables = ischema.tables
|
|
s = (
|
|
sql.select(tables.c.table_name)
|
|
.where(
|
|
sql.and_(
|
|
tables.c.table_schema == owner,
|
|
tables.c.table_type == "BASE TABLE",
|
|
)
|
|
)
|
|
.order_by(tables.c.table_name)
|
|
)
|
|
table_names = [r[0] for r in connection.execute(s)]
|
|
return table_names
|
|
|
|
@reflection.cache
|
|
@_db_plus_owner_listing
|
|
def get_view_names(self, connection, dbname, owner, schema, **kw):
|
|
tables = ischema.tables
|
|
s = (
|
|
sql.select(tables.c.table_name)
|
|
.where(
|
|
sql.and_(
|
|
tables.c.table_schema == owner,
|
|
tables.c.table_type == "VIEW",
|
|
)
|
|
)
|
|
.order_by(tables.c.table_name)
|
|
)
|
|
view_names = [r[0] for r in connection.execute(s)]
|
|
return view_names
|
|
|
|
@reflection.cache
|
|
@_db_plus_owner
|
|
def get_indexes(self, connection, tablename, dbname, owner, schema, **kw):
|
|
filter_definition = (
|
|
"ind.filter_definition"
|
|
if self.server_version_info >= MS_2008_VERSION
|
|
else "NULL as filter_definition"
|
|
)
|
|
rp = connection.execution_options(future_result=True).execute(
|
|
sql.text(
|
|
"select ind.index_id, ind.is_unique, ind.name, "
|
|
"%s "
|
|
"from sys.indexes as ind join sys.tables as tab on "
|
|
"ind.object_id=tab.object_id "
|
|
"join sys.schemas as sch on sch.schema_id=tab.schema_id "
|
|
"where tab.name = :tabname "
|
|
"and sch.name=:schname "
|
|
"and ind.is_primary_key=0 and ind.type != 0"
|
|
% filter_definition
|
|
)
|
|
.bindparams(
|
|
sql.bindparam("tabname", tablename, ischema.CoerceUnicode()),
|
|
sql.bindparam("schname", owner, ischema.CoerceUnicode()),
|
|
)
|
|
.columns(name=sqltypes.Unicode())
|
|
)
|
|
indexes = {}
|
|
for row in rp.mappings():
|
|
indexes[row["index_id"]] = {
|
|
"name": row["name"],
|
|
"unique": row["is_unique"] == 1,
|
|
"column_names": [],
|
|
"include_columns": [],
|
|
}
|
|
|
|
if row["filter_definition"] is not None:
|
|
indexes[row["index_id"]].setdefault("dialect_options", {})[
|
|
"mssql_where"
|
|
] = row["filter_definition"]
|
|
|
|
rp = connection.execution_options(future_result=True).execute(
|
|
sql.text(
|
|
"select ind_col.index_id, ind_col.object_id, col.name, "
|
|
"ind_col.is_included_column "
|
|
"from sys.columns as col "
|
|
"join sys.tables as tab on tab.object_id=col.object_id "
|
|
"join sys.index_columns as ind_col on "
|
|
"(ind_col.column_id=col.column_id and "
|
|
"ind_col.object_id=tab.object_id) "
|
|
"join sys.schemas as sch on sch.schema_id=tab.schema_id "
|
|
"where tab.name=:tabname "
|
|
"and sch.name=:schname"
|
|
)
|
|
.bindparams(
|
|
sql.bindparam("tabname", tablename, ischema.CoerceUnicode()),
|
|
sql.bindparam("schname", owner, ischema.CoerceUnicode()),
|
|
)
|
|
.columns(name=sqltypes.Unicode())
|
|
)
|
|
for row in rp.mappings():
|
|
if row["index_id"] in indexes:
|
|
if row["is_included_column"]:
|
|
indexes[row["index_id"]]["include_columns"].append(
|
|
row["name"]
|
|
)
|
|
else:
|
|
indexes[row["index_id"]]["column_names"].append(
|
|
row["name"]
|
|
)
|
|
|
|
return list(indexes.values())
|
|
|
|
@reflection.cache
|
|
@_db_plus_owner
|
|
def get_view_definition(
|
|
self, connection, viewname, dbname, owner, schema, **kw
|
|
):
|
|
rp = connection.execute(
|
|
sql.text(
|
|
"select definition from sys.sql_modules as mod, "
|
|
"sys.views as views, "
|
|
"sys.schemas as sch"
|
|
" where "
|
|
"mod.object_id=views.object_id and "
|
|
"views.schema_id=sch.schema_id and "
|
|
"views.name=:viewname and sch.name=:schname"
|
|
).bindparams(
|
|
sql.bindparam("viewname", viewname, ischema.CoerceUnicode()),
|
|
sql.bindparam("schname", owner, ischema.CoerceUnicode()),
|
|
)
|
|
)
|
|
|
|
if rp:
|
|
view_def = rp.scalar()
|
|
return view_def
|
|
|
|
def _temp_table_name_like_pattern(self, tablename):
|
|
return tablename + (("___%") if not tablename.startswith("##") else "")
|
|
|
|
def _get_internal_temp_table_name(self, connection, tablename):
|
|
# it's likely that schema is always "dbo", but since we can
|
|
# get it here, let's get it.
|
|
# see https://stackoverflow.com/questions/8311959/
|
|
# specifying-schema-for-temporary-tables
|
|
|
|
try:
|
|
return connection.execute(
|
|
sql.text(
|
|
"select table_schema, table_name "
|
|
"from tempdb.information_schema.tables "
|
|
"where table_name like :p1"
|
|
),
|
|
{"p1": self._temp_table_name_like_pattern(tablename)},
|
|
).one()
|
|
except exc.MultipleResultsFound as me:
|
|
util.raise_(
|
|
exc.UnreflectableTableError(
|
|
"Found more than one temporary table named '%s' in tempdb "
|
|
"at this time. Cannot reliably resolve that name to its "
|
|
"internal table name." % tablename
|
|
),
|
|
replace_context=me,
|
|
)
|
|
except exc.NoResultFound as ne:
|
|
util.raise_(
|
|
exc.NoSuchTableError(
|
|
"Unable to find a temporary table named '%s' in tempdb."
|
|
% tablename
|
|
),
|
|
replace_context=ne,
|
|
)
|
|
|
|
@reflection.cache
|
|
@_db_plus_owner
|
|
def get_columns(self, connection, tablename, dbname, owner, schema, **kw):
|
|
is_temp_table = tablename.startswith("#")
|
|
if is_temp_table:
|
|
owner, tablename = self._get_internal_temp_table_name(
|
|
connection, tablename
|
|
)
|
|
|
|
columns = ischema.mssql_temp_table_columns
|
|
else:
|
|
columns = ischema.columns
|
|
|
|
computed_cols = ischema.computed_columns
|
|
identity_cols = ischema.identity_columns
|
|
if owner:
|
|
whereclause = sql.and_(
|
|
columns.c.table_name == tablename,
|
|
columns.c.table_schema == owner,
|
|
)
|
|
full_name = columns.c.table_schema + "." + columns.c.table_name
|
|
else:
|
|
whereclause = columns.c.table_name == tablename
|
|
full_name = columns.c.table_name
|
|
|
|
join = columns.join(
|
|
computed_cols,
|
|
onclause=sql.and_(
|
|
computed_cols.c.object_id == func.object_id(full_name),
|
|
computed_cols.c.name == columns.c.column_name,
|
|
),
|
|
isouter=True,
|
|
).join(
|
|
identity_cols,
|
|
onclause=sql.and_(
|
|
identity_cols.c.object_id == func.object_id(full_name),
|
|
identity_cols.c.name == columns.c.column_name,
|
|
),
|
|
isouter=True,
|
|
)
|
|
|
|
if self._supports_nvarchar_max:
|
|
computed_definition = computed_cols.c.definition
|
|
else:
|
|
# tds_version 4.2 does not support NVARCHAR(MAX)
|
|
computed_definition = sql.cast(
|
|
computed_cols.c.definition, NVARCHAR(4000)
|
|
)
|
|
|
|
s = (
|
|
sql.select(
|
|
columns,
|
|
computed_definition,
|
|
computed_cols.c.is_persisted,
|
|
identity_cols.c.is_identity,
|
|
identity_cols.c.seed_value,
|
|
identity_cols.c.increment_value,
|
|
)
|
|
.where(whereclause)
|
|
.select_from(join)
|
|
.order_by(columns.c.ordinal_position)
|
|
)
|
|
|
|
c = connection.execution_options(future_result=True).execute(s)
|
|
|
|
cols = []
|
|
for row in c.mappings():
|
|
name = row[columns.c.column_name]
|
|
type_ = row[columns.c.data_type]
|
|
nullable = row[columns.c.is_nullable] == "YES"
|
|
charlen = row[columns.c.character_maximum_length]
|
|
numericprec = row[columns.c.numeric_precision]
|
|
numericscale = row[columns.c.numeric_scale]
|
|
default = row[columns.c.column_default]
|
|
collation = row[columns.c.collation_name]
|
|
definition = row[computed_definition]
|
|
is_persisted = row[computed_cols.c.is_persisted]
|
|
is_identity = row[identity_cols.c.is_identity]
|
|
identity_start = row[identity_cols.c.seed_value]
|
|
identity_increment = row[identity_cols.c.increment_value]
|
|
|
|
coltype = self.ischema_names.get(type_, None)
|
|
|
|
kwargs = {}
|
|
if coltype in (
|
|
MSString,
|
|
MSChar,
|
|
MSNVarchar,
|
|
MSNChar,
|
|
MSText,
|
|
MSNText,
|
|
MSBinary,
|
|
MSVarBinary,
|
|
sqltypes.LargeBinary,
|
|
):
|
|
if charlen == -1:
|
|
charlen = None
|
|
kwargs["length"] = charlen
|
|
if collation:
|
|
kwargs["collation"] = collation
|
|
|
|
if coltype is None:
|
|
util.warn(
|
|
"Did not recognize type '%s' of column '%s'"
|
|
% (type_, name)
|
|
)
|
|
coltype = sqltypes.NULLTYPE
|
|
else:
|
|
if issubclass(coltype, sqltypes.Numeric):
|
|
kwargs["precision"] = numericprec
|
|
|
|
if not issubclass(coltype, sqltypes.Float):
|
|
kwargs["scale"] = numericscale
|
|
|
|
coltype = coltype(**kwargs)
|
|
cdict = {
|
|
"name": name,
|
|
"type": coltype,
|
|
"nullable": nullable,
|
|
"default": default,
|
|
"autoincrement": is_identity is not None,
|
|
}
|
|
|
|
if definition is not None and is_persisted is not None:
|
|
cdict["computed"] = {
|
|
"sqltext": definition,
|
|
"persisted": is_persisted,
|
|
}
|
|
|
|
if is_identity is not None:
|
|
# identity_start and identity_increment are Decimal or None
|
|
if identity_start is None or identity_increment is None:
|
|
cdict["identity"] = {}
|
|
else:
|
|
if isinstance(coltype, sqltypes.BigInteger):
|
|
start = compat.long_type(identity_start)
|
|
increment = compat.long_type(identity_increment)
|
|
elif isinstance(coltype, sqltypes.Integer):
|
|
start = int(identity_start)
|
|
increment = int(identity_increment)
|
|
else:
|
|
start = identity_start
|
|
increment = identity_increment
|
|
|
|
cdict["identity"] = {
|
|
"start": start,
|
|
"increment": increment,
|
|
}
|
|
|
|
cols.append(cdict)
|
|
|
|
return cols
|
|
|
|
@reflection.cache
|
|
@_db_plus_owner
|
|
def get_pk_constraint(
|
|
self, connection, tablename, dbname, owner, schema, **kw
|
|
):
|
|
pkeys = []
|
|
TC = ischema.constraints
|
|
C = ischema.key_constraints.alias("C")
|
|
|
|
# Primary key constraints
|
|
s = (
|
|
sql.select(
|
|
C.c.column_name, TC.c.constraint_type, C.c.constraint_name
|
|
)
|
|
.where(
|
|
sql.and_(
|
|
TC.c.constraint_name == C.c.constraint_name,
|
|
TC.c.table_schema == C.c.table_schema,
|
|
C.c.table_name == tablename,
|
|
C.c.table_schema == owner,
|
|
),
|
|
)
|
|
.order_by(TC.c.constraint_name, C.c.ordinal_position)
|
|
)
|
|
c = connection.execution_options(future_result=True).execute(s)
|
|
constraint_name = None
|
|
for row in c.mappings():
|
|
if "PRIMARY" in row[TC.c.constraint_type.name]:
|
|
pkeys.append(row["COLUMN_NAME"])
|
|
if constraint_name is None:
|
|
constraint_name = row[C.c.constraint_name.name]
|
|
return {"constrained_columns": pkeys, "name": constraint_name}
|
|
|
|
@reflection.cache
|
|
@_db_plus_owner
|
|
def get_foreign_keys(
|
|
self, connection, tablename, dbname, owner, schema, **kw
|
|
):
|
|
RR = ischema.ref_constraints
|
|
C = ischema.key_constraints.alias("C")
|
|
R = ischema.key_constraints.alias("R")
|
|
# Foreign key constraints
|
|
s = (
|
|
sql.select(
|
|
C.c.column_name,
|
|
R.c.table_schema,
|
|
R.c.table_name,
|
|
R.c.column_name,
|
|
RR.c.constraint_name,
|
|
RR.c.match_option,
|
|
RR.c.update_rule,
|
|
RR.c.delete_rule,
|
|
)
|
|
.where(
|
|
sql.and_(
|
|
C.c.table_name == tablename,
|
|
C.c.table_schema == owner,
|
|
RR.c.constraint_schema == C.c.table_schema,
|
|
C.c.constraint_name == RR.c.constraint_name,
|
|
R.c.constraint_name == RR.c.unique_constraint_name,
|
|
R.c.constraint_schema == RR.c.unique_constraint_schema,
|
|
C.c.ordinal_position == R.c.ordinal_position,
|
|
)
|
|
)
|
|
.order_by(RR.c.constraint_name, R.c.ordinal_position)
|
|
)
|
|
|
|
# group rows by constraint ID, to handle multi-column FKs
|
|
fkeys = []
|
|
|
|
def fkey_rec():
|
|
return {
|
|
"name": None,
|
|
"constrained_columns": [],
|
|
"referred_schema": None,
|
|
"referred_table": None,
|
|
"referred_columns": [],
|
|
}
|
|
|
|
fkeys = util.defaultdict(fkey_rec)
|
|
|
|
for r in connection.execute(s).fetchall():
|
|
scol, rschema, rtbl, rcol, rfknm, fkmatch, fkuprule, fkdelrule = r
|
|
|
|
rec = fkeys[rfknm]
|
|
rec["name"] = rfknm
|
|
if not rec["referred_table"]:
|
|
rec["referred_table"] = rtbl
|
|
if schema is not None or owner != rschema:
|
|
if dbname:
|
|
rschema = dbname + "." + rschema
|
|
rec["referred_schema"] = rschema
|
|
|
|
local_cols, remote_cols = (
|
|
rec["constrained_columns"],
|
|
rec["referred_columns"],
|
|
)
|
|
|
|
local_cols.append(scol)
|
|
remote_cols.append(rcol)
|
|
|
|
return list(fkeys.values())
|