Re: Questions about Exists-Not exists clause - Mailing list pgsql-novice

>  > I've got, imagine, the next two tables:
>  >
>  > table A:
>  >
>  > field1    char(3)
>  > field2    varchar(50)
>  > field3    numeric(6)
>  >
>  >
>  > table B:
>  >
>  > field4    date
>  > field5    time
>  > field6    numeric(6)
>  >
>  >
>  > I need to know which rows in table A are not in table B, and the join
>  > fields are the two numeric ones (field3 and field6).
>
>SELECT * FROM A WHERE NOT EXISTS (SELECT NULL FROM B WHERE
>A.field3=B.field6);

I did this recently, using
SELECT * FROM A WHERE field3 NOT IN (SELECT field6 FROM B)

Now if this is totally wrong tell me *gently*, it's the first
question I felt I was up to to answer :-)

Regards,

     Martin
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