Hey!!! thanks thanks thanks to all of you!. Your just wonderfull and the help you provide is priceless.
I think I will solve my problem now. I've read about the use of variables in the manual but It would have taken me a lot of time to figure something like this. Thanks again and to all the rest of the people who answered my question Gratefully Mauricio On Fri, 2004-08-13 at 11:55, Keith Ivey wrote: > Mauricio Pellegrini wrote: > > >and would like to obtain this result from a query > > > > Col1 Col2 Col3 > > 1 20 20 > > 1 10 30 > > 1 20 50 > > 2 10 10 > > 2 5 15 > > 3 10 10 > > > >Column Col3 should carry forward and sum values from Col2 > > > Something like this should work, using two variables, @total and @prev: > > SELECT Col1, Col2, @total := IF(@prev = Col1, @total + Col2, Col2 + > (@prev := Col1) - Col1) > FROM table_name > ORDER BY Col1; > > The way I'm setting @prev every time Col1 changes is a bit klugy (having > to add it in and > then subtract Col1 to fix it), but it seems to work. > > Hmm, if you change the order of the result columns you can avoid the kluge: > > SELECT Col2, @total := IF(@prev = Col1, @total + Col2, Col2), @prev > := Col1 > FROM table_name > ORDER BY Col1; -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
