Jeg kører eksemplet fra følgende webside:
MySQL:: MySQL 5.0 Reference Manual:: 12.1.11 UDGØRE Udløsningsmængderne Syntaks
og problemet er, der udløser ikke kan defineres af en eller anden grund:

CREATE DATABASE IF NOT EXISTS triggertest;
USE triggertest;
CREATE TABLE test1(a1 INT);
CREATE TABLE test2(a2 INT);
CREATE TABLE test3(a3 INT NOT NULL AUTO_INCREMENT PRIMARY KEY);
CREATE TABLE test4(
  a4 INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  b4 INT DEFAULT 0
);

delimiter |

CREATE TRIGGER testref BEFORE INSERT ON test1
  FOR EACH ROW BEGIN
    INSERT INTO test2 SET a2 = NEW.a1;
    DELETE FROM test3 WHERE a3 = NEW.a1;
    UPDATE test4 SET b4 = b4 + 1 WHERE a4 = NEW.a1;
  END;
|

delimiter ;

Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'delimiter | CREATE TRIGGER testref BEFORE INSERT ON test1 FOR EACH ROW BE' at line 1

# mysql -v
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 164
Server version: 5.1.28-rc FreeBSD port: mysql-server-5.1.28_1