Re: Non-aggregate values attached to aggregates?

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От Klint Gore
Тема Re: Non-aggregate values attached to aggregates?
Дата
Msg-id 41C20DD5326.DCDAKG@129.180.47.120
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Ответ на Non-aggregate values attached to aggregates?  (Benjamin Smith <lists@benjamindsmith.com>)
Список pgsql-general
On Thu, 16 Dec 2004 13:38:19 -0800, Benjamin Smith <lists@benjamindsmith.com> wrote:
> I have a list of students, and a list of enrollment records, and I'm trying to
> get a list of students and their most recent enrollment/disenrollment dates.

just subselect the max date for the student_id in the where clause.

select students.name,
       enrollments.start,
       enrollments.finish
>from students, enrollments
where enrollments.students_id = students.id
and enrollments.start =
   (select max(e1.start)
    from enrollments e1
    where e1.student_id = students.id)

klint.

+---------------------------------------+-----------------+
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: EMail   : kg@kgb.une.edu.au           :  slang - the    :
: Snail   : A.B.R.I.                    :  possibilities  :
: Mail      University of New England   :  are useless"   :
:           Armidale NSW 2351 Australia :     L.J.J.      :
: Fax     : +61 2 6772 5376             :                 :
+---------------------------------------+-----------------+

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