On Sun, Oct 30, 2005 at 03:52:23PM +0100, Tino Wildenhain wrote: > Am Sonntag, den 30.10.2005, 06:29 -0800 schrieb David Fetter: > > On Fri, Oct 28, 2005 at 09:57:03PM -0400, blackwater dev wrote: > > > In MySQL, I can use the replace statement which either updates > > > the data there or inserts it. Is there a comporable syntax to > > > use in postgreSQL? > > > > Not really, but here's an example which doesn't have the > > brokenness of MySQL's REPLACE INTO and doesn't have the race > > conditions that some others' proposals have. > > > > http://developer.postgresql.org/docs/postgres/plpgsql-control-structures.html#PLPGSQL-ERROR-TRAPPING > > > > Of course, it's not as nice and flexible as the SQL standard > > MERGE, but until that day comes, you can use that example. > > In most cases, just DELETE and then INSERT should work perfectly. > (UPDATE and MERGE would cause dead tuples in the same way so in the > end they are only syntactical sugar) > > Another way is a rule for insert which turns it into an update in > case the desired tuple is already existent. That has a race condition in it. What happens if something deletes the tuple between the attempted INSERT and the UPDATE? Cheers, D -- David Fetter david@xxxxxxxxxx http://fetter.org/ phone: +1 510 893 6100 mobile: +1 415 235 3778 Remember to vote! ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
