SELECT SUM(column) INTO @variable in MySQL Trigger -

select sum(column) @variable tabl2 column2 = new.column in mysql update trigger returns null.

my code follows

create trigger `users_update` after update on `users`  each row begin     declare profit double default 0;      select sum(profit) @profit trades login = new.login , profit > 0;      update user_details set profit = @profit login = new.login; end; 

however same query when executed separately data. driving me crazy. please can suggest going wrong?

try 1 of this:

create trigger `users_update` after update on `users`  each row begin     declare profit double default 0;      select @profit:=sum(profit) trades login = new.login , profit > 0;      update user_details set profit = @profit login = new.login; end;  or if want use into:  create trigger `users_update` after update on `users`  each row begin     declare profit double default 0;      select sum(profit) trades login = new.login , profit > 0 @profit;      update user_details set profit = @profit login = new.login; end;