>>>What version of VFP?
>>>How about (Just in case you use VFP9):
>>>

>>>update mytable set flag = "1";
>>>       FROM mytable;
>>>INNER JOIN (SELECT f1 from look_up group by f1 having count(*) = 1) Tbl1 ON MyTable.F1 = Tbl1.F1
>>>INNER JOIN (SELECT f2 from look_up group by f2 having count(*) = 1) Tbl2 ON MyTable.F2 = Tbl1.F2
>>>

>>
>>That works, but I was never asking for an alternate solution to the update, I managed to get around it fine, I was asking if anyone knows why the update which appears to be the same query as the select was giving me the too complex error when the select works ok.
>
>What is your VFP version and SP?
>
>Check http://fox.wikis.com/wc.dll?Wiki~VFP9SP1BugFixList, similar error is mentioned there though applying to a different situation.

vfp9 sp2