Refs #31320 -- Warned against using BEGIN/COMMIT in RunSQL.

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Adam Johnson 2020-04-01 09:58:41 +01:00 committed by GitHub
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@ -252,6 +252,12 @@ features of database backends that Django doesn't support directly.
the database. On most database backends (all but PostgreSQL), Django will
split the SQL into individual statements prior to executing them.
.. warning::
On PostgreSQL and SQLite, only use ``BEGIN`` or ``COMMIT`` in your SQL in
:ref:`non-atomic migrations <non-atomic-migrations>`, to avoid breaking
Django's transaction state.
You can also pass a list of strings or 2-tuples. The latter is used for passing
queries and parameters in the same way as :ref:`cursor.execute()
<executing-custom-sql>`. These three operations are equivalent::
@ -275,12 +281,12 @@ insertion with a deletion::
If ``reverse_sql`` is ``None`` (the default), the ``RunSQL`` operation is
irreversible.
The ``state_operations`` argument is so you can supply operations that are
equivalent to the SQL in terms of project state; for example, if you are
The ``state_operations`` argument allows you to supply operations that are
equivalent to the SQL in terms of project state. For example, if you are
manually creating a column, you should pass in a list containing an ``AddField``
operation here so that the autodetector still has an up-to-date state of the
model (otherwise, when you next run ``makemigrations``, it won't see any
operation that adds that field and so will try to run it again). For example::
model. If you don't, when you next run ``makemigrations``, it won't see any
operation that adds that field and so will try to run it again. For example::
migrations.RunSQL(
"ALTER TABLE musician ADD COLUMN name varchar(255) NOT NULL;",