Thanks Eric and Alan for your help. I tried to apply your code to my problem and it works to a limited extent because the problem is more complicated than the example I gave in the post. I tries to simplify my exact problem but that didn't work out. So here is the problem that I trying to solve.
table1 (KEY, COL1) 0, 1 0, 2 1, 3 1, 4 2, 5 2, 6 3, 7 3, 8 table2 (KEY, X, Y) 0, 0, 0 1, 0, 1 2, 1, 0 3, 1, 1 What I would like to do is, like before, subtract COL1 from COL1 where table1.KEY = 0 and WHERE table1.KEY is IN (SELECT table2 WHERE X=0). But I want to do a vector subtraction instead of a scalar subtraction. So far I have UPDATE table1 set COL1 = COL1 - (SELECT COL1 WHERE table1.KEY = 0) WHERE table1.KEY IN (SELECT table2 WHERE X=0) The result I would like to get is table1 0, 0 //(1 - 1) 0, 0 //(2 - 2) 1, 2 //(3 - 1) 1, 2 //(4 - 2) 2, 5 2, 6 3, 7 3, 8 Instead I get 0, 0 //(1 - 1) 0, 1 //(2 - 1) 1, 2 //(3 - 1) 1, 3 //(4 - 1) 2, 5 2, 6 3, 7 3, 8 Is this possible in SQL? peterwinson1 wrote: > > Hello, > > I have a some what complex question about UPDATE. I have the following > table > > table1 (KEY, COL1) > > 0, 1 > 1, 2 > 2, 3 > 3, 4 > > What I would like to do is to UPDATE COL1 by subtracting the COL1 value > where KEY = 0 from the COL1 value of the current row so that the result > would be. > > 0, 0 > 1, 1 > 2, 2 > 3, 3 > > Can this be done in SQL? It does not have to be one UPDATE/SELECT > statement. > > Thank you > pw > > > -- View this message in context: http://old.nabble.com/Help-with-complex-UPDATE-question-tp29239594p29248382.html Sent from the SQLite mailing list archive at Nabble.com. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
