From: Daniel Henrique Alves Lima <email_daniel_h@yahoo.com.br>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-sql@postgresql.org
Subject: Re: Help to simplify sample query
Date: Tue, 09 Mar 2004 10:14:44 -0300
Message-ID: <404DC344.4070209@yahoo.com.br> (raw)
In-Reply-To: <21339.1078813653@sss.pgh.pa.us>
References: <404D5920.40104@yahoo.com.br>
<21339.1078813653@sss.pgh.pa.us>
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@yahoo.com.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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To: pgsql-sql@postgresql.org
Cc: email_daniel_h@yahoo.com.br, tgl@sss.pgh.pa.us
Subject: Re: Help to simplify sample query
In-Reply-To: <404DC344.4070209@yahoo.com.br>
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