From: | "Josh Berkus" <josh(at)agliodbs(dot)com> |
---|---|
To: | "Michael D(dot) Harlan" <r3mdh(at)beechwoodplace(dot)org>, pgsql-sql(at)postgresql(dot)org |
Subject: | Re: SQL Syntax / Logic question |
Date: | 2001-10-04 15:02:00 |
Message-ID: | web-141646@davinci.ethosmedia.com |
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Lists: | pgsql-sql |
Mike,
> select frienda, friendb from friends where (select
> schools.school from friends,schools where friends.frienda =
> schools.person) = (select schools.school from friends,schools where
> friends.friendb = schools.person);
Too complicated. You need to learn how to use JOINS and table aliases
(or find yourself some friends who know SQL!):
SELECT friends.frienda, friends.friendb
FROM friends JOIN schools schoola ON friends.frienda = schoola.person
JOIN schools schoolb ON friends.friendb = schoolb.person
WHERE schoola.school = schoolb.school
and, if it's possible that any particular person went to more than one
school, add:
GROUP BY frienda, friendb
Simple, neh?
-Josh
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