diff options
Diffstat (limited to 'docs/ref')
| -rw-r--r-- | docs/ref/migration-operations.txt | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/docs/ref/migration-operations.txt b/docs/ref/migration-operations.txt index 8169856f25..02afe67b51 100644 --- a/docs/ref/migration-operations.txt +++ b/docs/ref/migration-operations.txt @@ -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;", |