Re: query on query - Mailing list pgsql-general

From Luca Ferrari
Subject Re: query on query
Date
Msg-id CAKoxK+45XnSM+XQSEq8vb1owCppQ5v=gnG3CwHxX4E0TTVcboA@mail.gmail.com
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In response to query on query  (Jayadevan M <jayadevan.maymala@ibsplc.com>)
Responses Re: query on query
Re: query on query
List pgsql-general
On Fri, Jul 5, 2013 at 5:09 AM, Jayadevan M
<jayadevan.maymala@ibsplc.com> wrote:

>
> So each student may get counted many times, someone with 99 will be counted
> 10 times. Possible to do this with a fat query? The table will have many
> thousands of records.
>


Not sure I got the point, but I guess this is a good candidate for a CTE:

WITH RECURSIVE t(n) AS (
    VALUES (10)
  UNION ALL
    SELECT n+10 FROM t WHERE n < 50
)
select count(*), t.n from m, t where mark > t.n group by t.n;

Luca


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