Hi Nicholas, The query is across database query. dblink is needed for that task.
Hope it helps, John On Thu, Apr 30, 2009 at 3:07 PM, Edward W. Rouse <ero...@comsquared.com>wrote: > Can’t you use this? > > > > select name from database2.sr_1 where name not in (select name from > database2.pr_1); > > > > My test database VM isn’t running so I can’t test it, but I seem to > remember that that’s how I did it for a few queries of that type. This is > assuming the 2 databases are running on the same machine, like the way there > is template0 as the default and you add addition databases to the same > ‘instance’. If you are talking about 2 different database servers, then I > have no idea. > > > > Edward W. Rouse > > > > *From:* pgsql-sql-ow...@postgresql.org [mailto: > pgsql-sql-ow...@postgresql.org] *On Behalf Of *Nicholas I > *Sent:* Thursday, April 30, 2009 6:12 AM > *To:* Joshua Tolley > *Cc:* Adam Ruth; Pawel Socha; pgsql-sql@postgresql.org > *Subject:* Re: [SQL] Comparing two tables of different database > > > > Hi All, > > For example, > > There are two database. database1 and database 2; > > database1 has a table called pr_1 with the columns, id,name and time. > database2 has a table called sr_1 with the_columns id,name and time. > > i would like to find out the differences that is, find the names that > are not in sr_1 but in pr_1. > we can achieve this by the query, > > select name from sr_1 where name not in (select name from pr_1); > the above query will work in case of two tables in the same database. > > > But the problem is, these two tables are in different database. i did > not understand about the dblink. > > is there any exaples on dblink. can we do it without using dblink. > > -Nicholas I > > > >