On Sun, 01 Feb 2009 00:10:52 -0800 Mike Christensen <imaudi@xxxxxxxxxxx> wrote: > Figured out one way to do it, perhaps I can get some feedback on > if this is the best way.. Thanks! > > CREATE TEMP TABLE temp_ratings > ( > RecipeId uuid, > Rating smallint, > CONSTRAINT id_pk PRIMARY KEY (RecipeId) > ); > > INSERT INTO temp_ratings(RecipeId, Rating) > SELECT RecipeId, Avg(Rating) as Rating FROM RecipeRatings GROUP > BY RecipeId; > > UPDATE Recipes > SET Rating = tr.Rating > FROM temp_ratings as tr > WHERE Recipes.RecipeId = tr.RecipeId AND Recipes.Rating <> > tr.Rating You can have a similarly coincise form using insert into temp table http://www.postgresql.org/docs/8.3/interactive/sql-selectinto.html check what temporary table really means regarding transactions, functions and connections. [1] http://www.postgresql.org/docs/8.3/interactive/sql-createtable.html If specified, the table is created as a temporary table. Temporary tables are automatically dropped at the end of a session, or optionally at the end of the current transaction (see ON COMMIT below). Existing permanent tables with the same name are not visible to the current session while the temporary table exists, unless they are referenced with schema-qualified names. Any indexes created on a temporary table are automatically temporary as well. Optionally, GLOBAL or LOCAL can be written before TEMPORARY or TEMP. This makes no difference in PostgreSQL, but see Compatibility. of course depending on the context it may be useful to use "on commit" that seems to be only supported by the "more verbose" create path. Still the create path offer some shortcut to avoid to specify the schema of the temp table. create table like [1] and create table as that seems the most promising for your needs http://www.postgresql.org/docs/8.3/interactive/sql-createtableas.html not everything is yet as we dream it, but there is still a lot of syntactic sugar available to exploit. -- Ivan Sergio Borgonovo http://www.webthatworks.it -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
