Re: How to delete rows number 2,3,4...

Thank you all for your replies.


2010/10/8 Alban Hertroys <dalroi@solfertje.student.utwente.nl>:
> On 8 Oct 2010, at 8:59, A B wrote:
>
>> Hello.
>>
>> I have a table
>>
>> create table foo (
>> a serial,
>> b int,
>> c int,
>> .... more fields ...);
>>
>> and now I wish to remove for each combination of b and c,  all the
>> rows except the one with the highest value of a.
>
> Or said differently: Delete all the rows where there exists a value of A that is higher than the one in the current
row,given B and C are equal. 
>
> In SQL that is:
>
> DELETE FROM foo WHERE EXISTS (
>        SELECT 1
>          FROM foo
>         WHERE foo.a > a
>           AND foo.b = bar.b
>           AND foo.c = bar.c
> )
>
> Alban Hertroys
>
> --
> If you can't see the forest for the trees,
> cut the trees and you'll see there is no forest.
>
>
> !DSPAM:871,4caeeab7678305532215207!
>
>
>