| From: | Craig Ringer <craig(at)postnewspapers(dot)com(dot)au> |
|---|---|
| To: | Daniel Futerman <daniel(dot)futerman(at)gmail(dot)com> |
| Cc: | pgsql-general(at)postgresql(dot)org |
| Subject: | Re: Update Join Query |
| Date: | 2008-06-23 23:35:47 |
| Message-ID: | 48603353.4020006@postnewspapers.com.au |
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| Lists: | pgsql-general |
Daniel Futerman wrote:
> Is it possible to have UPDATE JOIN queries in PostgreSQL?
Yes:
UPDATE target
....
FROM othertable;
As far as I know Pg can only do an inner join on the update target. This
can be easily be turned into an outer join with something like:
UPDATE target
....
FROM target t LEFT OUTER JOIN othertable
WHERE target.id = t.id;
or similar. I haven't checked to see whether this results in an extra
scan in the query plan; you might want to use EXPLAIN ANALYZE to examine
how Pg will execute the query.
--
Craig Ringer
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