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-rw-r--r--lib/sqlalchemy/dialects/mysql/base.py42
-rw-r--r--lib/sqlalchemy/dialects/postgresql/base.py10
2 files changed, 39 insertions, 13 deletions
diff --git a/lib/sqlalchemy/dialects/mysql/base.py b/lib/sqlalchemy/dialects/mysql/base.py
index b04070162..b85e32db0 100644
--- a/lib/sqlalchemy/dialects/mysql/base.py
+++ b/lib/sqlalchemy/dialects/mysql/base.py
@@ -111,19 +111,45 @@ to be used.
Transaction Isolation Level
---------------------------
-:func:`.create_engine` accepts an :paramref:`.create_engine.isolation_level`
-parameter which results in the command ``SET SESSION
-TRANSACTION ISOLATION LEVEL <level>`` being invoked for
-every new connection. Valid values for this parameter are
-``READ COMMITTED``, ``READ UNCOMMITTED``,
-``REPEATABLE READ``, and ``SERIALIZABLE``::
+All MySQL dialects support setting of transaction isolation level
+both via a dialect-specific parameter :paramref:`.create_engine.isolation_level`
+accepted by :func:`.create_engine`,
+as well as the :paramref:`.Connection.execution_options.isolation_level`
+argument as passed to :meth:`.Connection.execution_options`.
+This feature works by issuing the command
+``SET SESSION TRANSACTION ISOLATION LEVEL <level>`` for
+each new connection. For the special AUTOCOMMIT isolation level, DBAPI-specific
+techniques are used.
+
+To set isolation level using :func:`.create_engine`::
engine = create_engine(
"mysql://scott:tiger@localhost/test",
isolation_level="READ UNCOMMITTED"
)
-.. versionadded:: 0.7.6
+To set using per-connection execution options::
+
+ connection = engine.connect()
+ connection = connection.execution_options(
+ isolation_level="READ COMMITTED"
+ )
+
+Valid values for ``isolation_level`` include:
+
+* ``READ COMMITTED``
+* ``READ UNCOMMITTED``
+* ``REPEATABLE READ``
+* ``SERIALIZABLE``
+* ``AUTOCOMMIT``
+
+The special ``AUTOCOMMIT`` value makes use of the various "autocommit"
+attributes provided by specific DBAPIs, and is currently supported by
+MySQLdb, MySQL-Client, MySQL-Connector Python, and PyMySQL. Using it,
+the MySQL connection will return true for the value of
+``SELECT @@autocommit;``.
+
+.. versionadded:: 1.1 - added support for the AUTOCOMMIT isolation level.
AUTO_INCREMENT Behavior
-----------------------
@@ -1439,6 +1465,8 @@ class MySQLDialect(default.DefaultDialect):
level = level.replace('_', ' ')
# adjust for ConnectionFairy being present
+ # allows attribute set e.g. "connection.autocommit = True"
+ # to work properly
if hasattr(connection, 'connection'):
connection = connection.connection
diff --git a/lib/sqlalchemy/dialects/postgresql/base.py b/lib/sqlalchemy/dialects/postgresql/base.py
index b16a82e04..c0a3708d4 100644
--- a/lib/sqlalchemy/dialects/postgresql/base.py
+++ b/lib/sqlalchemy/dialects/postgresql/base.py
@@ -50,11 +50,12 @@ Transaction Isolation Level
All Postgresql dialects support setting of transaction isolation level
both via a dialect-specific parameter :paramref:`.create_engine.isolation_level`
accepted by :func:`.create_engine`,
-as well as the ``isolation_level`` argument as passed to
+as well as the :paramref:`.Connection.execution_options.isolation_level` argument as passed to
:meth:`.Connection.execution_options`. When using a non-psycopg2 dialect,
this feature works by issuing the command
``SET SESSION CHARACTERISTICS AS TRANSACTION ISOLATION LEVEL <level>`` for
-each new connection.
+each new connection. For the special AUTOCOMMIT isolation level, DBAPI-specific
+techniques are used.
To set isolation level using :func:`.create_engine`::
@@ -76,10 +77,7 @@ Valid values for ``isolation_level`` include:
* ``READ UNCOMMITTED``
* ``REPEATABLE READ``
* ``SERIALIZABLE``
-
-The :mod:`~sqlalchemy.dialects.postgresql.psycopg2` and
-:mod:`~sqlalchemy.dialects.postgresql.pg8000` dialects also offer the
-special level ``AUTOCOMMIT``.
+* ``AUTOCOMMIT`` - on psycopg2 / pg8000 only
.. seealso::