In response to Otniel Michael :
> Hi All.
>
> Can help to create sql queries for this data :
>
> tabel A
> field1, field2, field3
> x1, y1, 5
> x1, y2, 1
> x2, y1, 2
> x2, y3, 4
> x1, y3, 4
>
> I want to get 2 record with the max value at field3 for each kombination of
> field1 :
>
> tabel B
> field1, field2, field3
> x1, y1, 5
> x1, y3, 4
> x2, y3, 4
> x2, y1, 2
>
> Anyone have an ideas?
Works since 8.4:
test=*# select * from table_a ;field1 | field2 | field3
--------+--------+--------x1 | y1 | 5x1 | y2 | 1x2 | y1 | 2x2 | y3 |
4x1 | y3 | 4
(5 rows)
test=*# select field1, field2, field3 from (select field1, field2,
field3, row_number() over(partition by field1 order by field3 desc) from
table_a order by field1, field3) foo where row_number < 3 order by
field1, field2;field1 | field2 | field3
--------+--------+--------x1 | y1 | 5x1 | y3 | 4x2 | y1 | 2x2 | y3 |
4
(4 rows)
Regards, Andreas
--
Andreas Kretschmer
Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header)
GnuPG-ID: 0x3FFF606C, privat 0x7F4584DA http://wwwkeys.de.pgp.net