"Viorel Dragomir" <[EMAIL PROTECTED]> writes: > Anyway, in real life this update modifies only one row with a value wich is > diff of null. It was really handy if it was specified the option ORDER for > the update command.
Are you hoping to produce a running total? That's very difficult in standard SQL. That would be very different from the query you asked for. Running totals, ranking, lead/lag, are all things that are very difficult to do in standard SQL. They don't fit in the unordered set model that SQL follows so doing them without special non-standard functions is very hard and inefficient. The functions to do them don't fit well within the SQL universe either, which might be why they don't exist yet in postgres. -- greg ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
