>You will need to use EXISTS criteria, e.g.
>
>

>SELECT TOP 10 Event.RO_No,Min(Event.DateTime) AS LastUpdate
> FROM Event
> where exists (select 1 from RO where RO.Ro_No = Event.Ro_No)
> GROUP BY Event.RO_No

>
>and then join with the RO the same way.
> ORDER BY MIN(Event.Datetime

Thanks, this is also another approach. I will take the one from Borislav for now. When I read it, it find it much simpler. Not sure however if it is more optimized.