Apparently I don't understand full outer joins....
От | Ben |
---|---|
Тема | Apparently I don't understand full outer joins.... |
Дата | |
Msg-id | Pine.LNX.4.44.0501251226110.9786-100000@localhost.localdomain обсуждение исходный текст |
Ответы |
Re: Apparently I don't understand full outer joins....
Re: Apparently I don't understand full outer joins.... Re: Apparently I don't understand full outer joins.... |
Список | pgsql-general |
I run this: select coalesce(a.n,0) as a, coalesce(b.n,0) as b, coalesce(a.s,b.s) as s from ( select 1 as n, 0 as s) a full outer join ( select 2 as n, 1 as s) b on a.s = b.s ... and get this: a | b | s ---+---+--- 1 | 0 | 0 0 | 2 | 1 (2 rows) Perfect! Now, I try to extend my understanding to 3 subselects: select coalesce(a.n,0) as a, coalesce(b.n,0) as b, coalesce(c.n,0) as c, coalesce(a.s,b.s,c.s) as s from ( select 1 as n, 0 as s) a full outer join ( select 1 as n, 1 as s) b full outer join ( select 2 as n, 2 as s) c on a.s = b.s and b.s = c.s .... and get a syntax error at the end of my query. Apparently what I'm trying to do doesn't make sense? Oh, this is on version 7.4, if that makes a difference. --- Ben Chobot Senior Technical Specialist, Washington Mutual 206-461-4005
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