>This kind of update seems to be very tricky.
>Are you using it in your programs ?
>
>>Think of what a SET RELATION does and imnplement it yourself. Issuing a SET RELATION causes a SEEK() to be performed in the child table whenever the record pointer is moved in the parent. Add the SEEK() logic to your WHERE clause and you should have it.

>>UPDATE Cursor1 ;
>>    SET Cursor1.SomeField=RCursor1.SomeField ;
>>    WHERE SEEK(Cursor1.LinkField,'RCursor','SomeTag')

>>

I've used derivations in the past. Nothing currently.

Why do you say it's tricky? I often use a combination of SQL and xBase syntax. It's one of reasons I like VFP.