Re: Add Missing From?

Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> Tom Lane wrote:
>> This description confuses two quite separate issues.

> Yea, it does.

> How is this text:

> * Allow DELETE to handle table aliases for self-joins

> There is no way to create a table alias for the deleted table for use
> in the DELETE WHERE clause. The agreed approach is to allow a USING
> clause to specify additional tables. UPDATE already has an optional
> FROM clause for this purpose.

Not a lot better. They really should be two separate issues, because we
could in theory do either without the other.

* Allow an alias to be provided for the target table in UPDATE/DELETE

This is not SQL-spec but many DBMSs allow it.

* Allow additional tables to be specified in DELETE for joining

UPDATE already allows this (UPDATE...FROM) and we need a similar
ability in DELETE. It's been agreed that the keyword should be
USING, to avoid anything so confusing as DELETE FROM a FROM b.

I have not looked to see whether or not there are already entries
similar to these.

regards, tom lane