MySQL trigger 'update on column' syntax
mysql, sql-update, syntax, triggers
Solution
You can't specify that the trigger is to be run only on the update of specific columns (an `UPDATE` affects the entire record), but you can test which columns have been updated within your trigger:
DELIMITER ;;
CREATE TRIGGER my_trigger BEFORE UPDATE ON TABLE_NAME FOR EACH ROW
IF NOT (NEW.col1 <=> OLD.col1 AND NEW.col2 <=> OLD.col2) THEN
SET NEW.col3 = NEW.col3 + 1;
END IF;;
DELIMITER ;
Problem
Can we use a MySQL trigger on update of specific columns, which updates another column in same table (same row) ``` create trigger my_trigger BEFORE UPDATE OF col1, col2 ON TABLE_NAME for each row set NEW.col3 = NEW.col3 +1; ``` I tried the above code using `UPDATE OF col1, col2` . It is not working in MySQL. What is the correct syntax, can somebody point me to some examples.