What is the index expression?


>I am using a where filter that looks like the following:
>
>STR(id, 19, 0) + STR(other_id, 5, 0) IN
>(SELECT MIN(STR(id, 19, 0) + STR(other_id, 5, 0)
>FROM tablex GROUP BY id)
>
>I am pulling the first record encountered for the ID field, and using that in a report. TableX has valid records in it. The error "Invalid Key Length" comes up when I execute the entire SQL. I swapped out the TableX for another table, let's say TableY. The query works fine for TableY.
>
>I looked at the Visual FoxPro 7.0 help for the error and figured it was an index problem. So I eliminated ALL of the indexes for ALL of the tables in the query. The error still persists!
>
>What was very interesting, the error did not occur in Visual FoxPro 8.0!
>
>Does anyone have any idea what is going on here?