join queries

"David M. Kaplan" wrote:

Hi,

I have a query which seems like it should easy, but isnt. I have two
tables, a and b that look like this:

a)

id | c1
--+--
1 | a
2 | b
3 | c

b)

id | c2
--+--
2 | b

and I would like to do a query which returns

id | c1 | c2
--+--+--
1 | a |
2 | b | b
3 | c |

The simplest thing I could find was

SELECT a.*, (SELECT b.c2 WHERE a.id=b.id) AS c2;

This works, but is extremely slow for more complex examples. Is there a
better way to do this in postgresql?? I think MS Access has inner and
outer joins to solve this problem. Is there a postgresql equivalent?

SELECT a.id, c1, c2 FROM a LEFT OUTER JOIN b ON a.id = b.id

This requires PostgreSQL 7.1

--
Oliver Elphick Oliver.Elphick@lfix.co.uk
Isle of Wight http://www.lfix.co.uk/oliver
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