Re: syntax for updating an aliased table

[Rick Genter <rick.genter@xxxxxxxxx>]

The UPDATE statement when multiple tables are involved always drives me nuts.

I think what you need to do is remove all of the "old." from the SET clause and use "triple." in the WHERE clause instead of "old." - and remove the old table alias from the UPDATE.

On Thu, May 26, 2011 at 9:38 AM, Andy Chambers <achambers@xxxxxxxx> wrote:

I'm confused about the correct syntax for updating an aliased table.  I want to update triple from triple_updates

where the data is different and tried to use the following....

update triple old

                           set

                              old.obln = new.obln,  old.ointv = new.ointv,  old.otime = new.otime,  old.oflt = new.oflt,  old.ostr = new.ostr,  old.oint = new.oint,  old.oda = new.oda,  old.uasid = new.uasid

                           from triple_update as new

                          where (old.s = new.s and

                                 old.g = new.g) and

                                ( old.obln <> new.obln or  old.ointv <> new.ointv or  old.otime <> new.otime or  old.oflt <> new.oflt or  old.ostr <> new.ostr or  old.oint <> new.oint or  old.oda <> new.oda or  old.uasid <> new.uasid)

...but postgres complains about not having column "old" in the triple table.  Putting an "as" between triple and old on the first line didn't make any difference.  If

I leave out the old alias, it complains about the columns being ambiguous.  How should the query above be changed to be syntactically correct?

Thanks,

Andy

--
Rick Genter
rick.genter@xxxxxxxxx