> 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' [email protected] [firebird-support] > Data: 29/07/2015 18.59.03 > A: [email protected] > 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] > > > > ------------------------------------ > Posted by: "Raffaele Confalone" <[email protected]> > ------------------------------------ > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > ++++++++ > > Visit http://www.firebirdsql.org and click the Documentation item on the > main (top) menu. Try FAQ and other links from the left-side menu there. > > Also search the knowledgebases at > http://www.ibphoenix.com/resources/documents/ > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > ++++++++ > ------------------------------------ > > Yahoo Groups Links > > >
