select f1,f2,f3,f4 from table1 EXCEPT ALL select f1,f2,f3,f4 from table2 http://www.postgresql.org/docs/8.1/static/sql-select.html On 1/27/06, Stefano B. <stefano.bonnin@xxxxxxxx> wrote: > > Hi, > > I have two identical tables > > table1 (f1,f2,f3,f4 primary key (f1,f2,f3,f4)) > > table2 (g1,g2,g3,g4 primary key (g1,g2,g3,g4)) > > How can I find the difference between the two tables? > table1 has 10000 records > table2 has 9900 records (these records are in table1 as well) > > I'd like to find 100 missing records. > I have try this query > > select f1,f2,f3,f4 from table1 where (f1,f2,f3,f4) NOT IN (select > f1,f2,f3,f4 from table2) > > but it seems not work (as I want). It returns me no records. If I use the IN > clause it returns me all 10000 table1 records. > > Thanks in advance > Stefano
