Re: Can i customize null-padding for outer joins?
От | A. Kretschmer |
---|---|
Тема | Re: Can i customize null-padding for outer joins? |
Дата | |
Msg-id | 20091001064021.GA25444@a-kretschmer.de обсуждение исходный текст |
Ответ на | Can i customize null-padding for outer joins? (Shruthi A <shruthi.iisc@gmail.com>) |
Список | pgsql-sql |
In response to Shruthi A : > Hello, > > I have a query where I full-outer-join 2 tables, and all the columns other than > the join column are numerical columns. For my further calculations i need to > pad the unmatched tuples with 0 (zero) instead of NULL so that I can perform > meaningful mathematical calculations on them. Is this currently possible? You can use COALESCE() in your numerical calculation, for instance: test=*# create table foo (n numeric); CREATE TABLE test=*# insert into foo values (1),(NULL),(NULL); INSERT 0 3 test=*# select avg(n) from foo; avg ------------------------1.00000000000000000000 (1 row) test=*# select avg(coalesce(n,0)) from foo; avg ------------------------0.33333333333333333333 (1 row) Or use coalesce in your join-statement: select coalesce(column,0) ... Regards, Andreas -- Andreas Kretschmer Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header)
В списке pgsql-sql по дате отправления: