| From: | Daniel Henrique Alves Lima <email_daniel_h(at)yahoo(dot)com(dot)br> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | pgsql-sql(at)postgresql(dot)org |
| Subject: | Re: Help to simplify sample query |
| Date: | 2004-03-09 13:14:44 |
| Message-ID: | 404DC344.4070209@yahoo.com.br |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-sql |
How about this:
select cd_area from area a1 where
not exists ((select 1,2 union select 98,45 union select 11,0) except
select c2.cd_teacher,c2.cd_course from teacher_course c2 where
c2.cd_course=a1.course)
?
Tom Lane wrote:
>Daniel Henrique Alves Lima <email_daniel_h(at)yahoo(dot)com(dot)br> writes:
>
>
>> I don't think this is possible, but: Is there a efficient way to
>>compare if the result of a query is a superset of the result of another ?
>>
>>
>
>Perhaps do "SELECT foo EXCEPT SELECT bar" and see if you get anything?
>
> regards, tom lane
>
>
>
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