Fire a trigger after the update of specific columns in MySQL
You can't trigger on a particular column update in SQL. It is applied on a row.
You can put your condition for columm in your trigger with an IF statement, as below:
DELIMITER //CREATE TRIGGER myTrigger AFTER UPDATE ON myTableFOR EACH ROWBEGIN IF !(NEW.column1 <=> OLD.column1) THEN --type your statements here END IF;END;//DELIMITER ;
You can't specify only to fire on specific column changes. But for a record change on a table you can do
delimiter |CREATE TRIGGER myTrigger AFTER UPDATE ON myTableFOR EACH ROWBEGIN ...END|delimiter ;In your trigger you can refer to old and new content of a column like this
if NEW.column1 <> OLD.column1 ...