Helen Borrie wrote:

> It's not intended for columns that exist in the database (such as a COMPUTED BY column or any regular >column) - it is for non-database columns that are computed by a query, i.e expressions and subselects that >output as if they were columns...also for CalculatedFields. Its purpose is to tell the parser not to try >to match it to a database column for e.g. a WHERE criterion.

Thanks for explaining this !

Harald