Mysql数据库的触发程序

 /**
 **创建表
 */
 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
 );
 /**
 **创建触发程序
 */
 DROP TRIGGER IF EXISTS testref;
 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 ;

 /**
 ** 插入初始数据
 */
 INSERT INTO test3(a3) VALUES (NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL);

 INSERT INTO test4(a4) VALUES (0),(0),(0),(0),(0),(0),(0),(0),(0),(0);

 /**
 ** 测试触发过程
 */
 INSERT INTO test1 VALUES  (1),(3),(1),(7),(1),(8),(4),(4);