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Diffstat (limited to 'lib/sqlalchemy/ext/compiler.py')
| -rw-r--r-- | lib/sqlalchemy/ext/compiler.py | 50 |
1 files changed, 0 insertions, 50 deletions
diff --git a/lib/sqlalchemy/ext/compiler.py b/lib/sqlalchemy/ext/compiler.py index c7eb7cc32..354b0ca4a 100644 --- a/lib/sqlalchemy/ext/compiler.py +++ b/lib/sqlalchemy/ext/compiler.py @@ -103,10 +103,6 @@ Produces:: functionality is already available using the :meth:`_expression.Insert.from_select` method. -.. note:: - - The above ``InsertFromSelect`` construct probably wants to have "autocommit" - enabled. See :ref:`enabling_compiled_autocommit` for this step. Cross Compiling between SQL and DDL compilers --------------------------------------------- @@ -135,52 +131,6 @@ a bound parameter; when emitting DDL, bound parameters are typically not supported. -.. _enabling_compiled_autocommit: - -Enabling Autocommit on a Construct -================================== - -Recall from the section :ref:`autocommit` that the :class:`_engine.Engine`, -when -asked to execute a construct in the absence of a user-defined transaction, -detects if the given construct represents DML or DDL, that is, a data -modification or data definition statement, which requires (or may require, -in the case of DDL) that the transaction generated by the DBAPI be committed -(recall that DBAPI always has a transaction going on regardless of what -SQLAlchemy does). Checking for this is actually accomplished by checking for -the "autocommit" execution option on the construct. When building a -construct like an INSERT derivation, a new DDL type, or perhaps a stored -procedure that alters data, the "autocommit" option needs to be set in order -for the statement to function with "connectionless" execution -(as described in :ref:`dbengine_implicit`). - -Currently a quick way to do this is to subclass :class:`.Executable`, then -add the "autocommit" flag to the ``_execution_options`` dictionary (note this -is a "frozen" dictionary which supplies a generative ``union()`` method):: - - from sqlalchemy.sql.expression import Executable, ClauseElement - - class MyInsertThing(Executable, ClauseElement): - _execution_options = \ - Executable._execution_options.union({'autocommit': True}) - -More succinctly, if the construct is truly similar to an INSERT, UPDATE, or -DELETE, :class:`.UpdateBase` can be used, which already is a subclass -of :class:`.Executable`, :class:`_expression.ClauseElement` and includes the -``autocommit`` flag:: - - from sqlalchemy.sql.expression import UpdateBase - - class MyInsertThing(UpdateBase): - def __init__(self, ...): - ... - - - - -DDL elements that subclass :class:`.DDLElement` already have the -"autocommit" flag turned on. - |