A trigger is a stored program that is automatically executed ("triggered") in response to certain events occurring in the database. These events can include INSERT, UPDATE, or DELETE operations on a table.
Triggers are created using the CREATE TRIGGER statement.
Types Of Triggers in MYSQL
- Before Insert: Activated Before insert data in table.
- After Insert: Activated After insert data in table.
- Before Update: Activated Before update data in table.
- After Update: Activated After update data in table.
- Before Delete: Activated Before remove data in table.
- After Delete: Activated After remove data in table.
CREATE TRIGGER trigger_name
BEFORE|AFTER INSERT|UPDATE|DELETE ON table_name
FOR EACH ROW
BEGIN
-- Trigger body (SQL statements)
END;