From: | Noah Silverman <noah(at)allresearch(dot)com> |
---|---|
To: | pgsql-performance(at)postgresql(dot)org |
Subject: | Strange Join question |
Date: | 2003-01-17 17:28:35 |
Message-ID: | 1B62AFA4-2A41-11D7-8B2D-000393AA8F3C@allresearch.com |
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Thread: | |
Lists: | pgsql-performance |
Hi,
I have a challenging (for me) SQL question:
Two tables
(Note: these are fictitious, the real tables actually make sense, so no
need to re-design our table structure)
Table 1
id | name | count
------------------------
1 | foo | 10
1 | foo | 20
2 | bar | 100
Table 2
id | f1 | f2 | t1ref
-----------------------
1 | 10 | 20 | 1
2 | 50 | 40 | 2
The question:
I want to do the following select:
select table2.f1, table1.name from table1,table2 where table1.id =
table 2.id and table2.id = 2;
The problem is that I really only need the name from table2 returned
once. With this query, I get two records back. Clearly this is
because of the join that I am doing. Is there a different way to
perform this join, so that I only get back ONE record from table1 that
matches?
Thanks,
-Noah
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