support for deletion via multiple table query when synchronize_session=False

[Former user]

Is this not something that could be enabled?

[Former user]

(Assuming that the query only selected from one table.)

[Mike Bayer]

the issue is not really the synchronize session part, its that the SQL expression language doesn't support DELETE with multiple FROM clauses. Its not standard SQL. only MySQL supports it, and PG kind of supports it via their "USING" extension. In that sense this ticket is pretty much a dupe of #959.

as an aside, the same effect as DELETE..FROM multiple tables can be achieved using IN or EXISTS in the WHERE clause of the DELETE.