diff options
Diffstat (limited to 'lib/sqlalchemy/dialects/mssql/base.py')
| -rw-r--r-- | lib/sqlalchemy/dialects/mssql/base.py | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/lib/sqlalchemy/dialects/mssql/base.py b/lib/sqlalchemy/dialects/mssql/base.py index 31745d600..808fdf16f 100644 --- a/lib/sqlalchemy/dialects/mssql/base.py +++ b/lib/sqlalchemy/dialects/mssql/base.py @@ -251,18 +251,11 @@ The process for fetching this value has several variants: INSERT INTO t (x) OUTPUT inserted.id VALUES (?) - As of SQLAlchemy 2.0, the :ref:`engine_insertmanyvalues` feature is also - used by default to optimize many-row INSERT statements; for SQL Server - the feature takes place for both RETURNING and-non RETURNING - INSERT statements. - -* The value of :paramref:`_sa.create_engine.insertmanyvalues_page_size` - defaults to 1000, however the ultimate page size for a particular INSERT - statement may be limited further, based on an observed limit of - 2100 bound parameters for a single statement in SQL Server. - The page size may also be modified on a per-engine - or per-statement basis; see the section - :ref:`engine_insertmanyvalues_page_size` for details. + .. note:: SQLAlchemy 2.0 introduced the :ref:`engine_insertmanyvalues` + feature for SQL Server, which is used by default to optimize many-row + INSERT statements; however as of SQLAlchemy 2.0.9 this feature had + to be turned off for SQL Server as the database does not support + deterministic RETURNING of INSERT rows for a multi-row INSERT statement. * When RETURNING is not available or has been disabled via ``implicit_returning=False``, either the ``scope_identity()`` function or @@ -3017,7 +3010,8 @@ class MSDialect(default.DefaultDialect): # may be changed at server inspection time for older SQL server versions supports_multivalues_insert = True - use_insertmanyvalues = True + # disabled due to #9603 + use_insertmanyvalues = False # note pyodbc will set this to False if fast_executemany is set, # as of SQLAlchemy 2.0.9 @@ -3085,6 +3079,14 @@ class MSDialect(default.DefaultDialect): super().__init__(**opts) + if self.use_insertmanyvalues: + raise exc.ArgumentError( + "The use_insertmanyvalues feature on SQL Server is currently " + "not safe to use, as returned result rows may be returned in " + "random order. Ensure use_insertmanyvalues is left at its " + "default of False (this setting changed in SQLAlchemy 2.0.9)" + ) + self._json_serializer = json_serializer self._json_deserializer = json_deserializer |