> This is solution:
> select * from tabella A where Group_ID in (Select min(Group_ID) in tabella B
> where B.ID=A.ID);

Are you sure that works? It doesn't see to answer Maya original question.

It also would read n^2 rows from the table.


Sean

>
> -------Messaggio originale-------
>
> Da: 'Leyne, Sean' Sean@... [firebird-support]
> Data: 29/07/2015 18.59.03
> A: firebird-support@yahoogroups.com
> Oggetto: [firebird-support] RE: Possible to use FIRST 1 inside a group by?
>
>
> Maya,
>
> > Might not be the most efficient method, but this works:
>
> Unfortunately, it is least efficient method -- you will read each table row
> n^2 times
>
> Try:
>
> SELECT
> T.ID
> T.GroupID
> T2.FKCode
> T2.Value
> FROM (
> select MIN (ID) as ID, GroupID
> from MyTable
> GROUP BY GroupID
> ) T
> JOIN MyTable T2 ON T2.ID = T.ID
>
> Sean
>
>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
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