Subject: help with "delete joins"
From: Robert Treat <rtreat@webmd.net>
To: pgsql-sql@postgresql.org
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Date: 30 Jun 2003 18:26:38 -0400
Message-Id: <1057011998.24310.348.camel@camel>
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create table foo (a int, b int, c int, d text);

create table bar (a int, b int, c int);

insert into foo values (1,2,3,'a');
insert into foo values (1,2,4,'A');
insert into foo values (4,5,6,'b');
insert into foo values (7,8,9,'c');
insert into foo values (10,11,12,'d');

insert into bar values (1,2,3);
insert into bar values (7,8,9);
insert into bar values (10,11,12);

what i want to do is:

delete * from foo where not (foo.a = bar.a and foo.b=bar.b and
foo.c=bar.c) ;

so i end up with 

postgres=# select * from foo; 
 a | b | c | d 
---+---+---+---
 1 | 2 | 4 | A
 4 | 5 | 6 | b
(2 rows)

but thats not valid sql, is there some way to accomplish this? 

Robert Treat