Re: " Adding missing FROM-clause entry for table .... " problem.

Bruno Wolff III <bruno(at)wolff(dot)to> writes:
> Christoph Haller <ch(at)rodos(dot)fzk(dot)de> wrote:
>> AFAIK, statements like
>> DELETE FROM t1 where t1.id = t2.id ;
>> are legal. Could the parser still work on this, if the feature is
>> removed?

> Only if a new syntax is added.

For UPDATE, we actually do have an extension syntax that allows naming
secondary tables explicitly:

UPDATE target SET ... FROM other-tables WHERE ...

The trouble with extending this to DELETE is that DELETE already uses
the keyword FROM. Seems like we are stuck with a choice between

DELETE FROM target FROM other-tables WHERE ...

DELETE FROM target, other-tables WHERE ...

both of which are bizarre and confusing to my eyes. I think that MySQL
uses the second form, which I like even less than the first (it obscures
the very fundamental semantic difference between the deletion target and
the other tables).

Or we could go off with a different keyword, perhaps

DELETE FROM target WITH other-tables WHERE ...

but that doesn't seem to pass the low-astonishment test either.

Comments? It would not be difficult to implement any of these
alternatives. <hhg>okay, you think it's so easy, *you* decide
what color it should be</hhg>

regards, tom lane