CREATE TRIGGER name,time,event ON table_name FOR EACH ROW trigger_stmt

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 ;INSERT INTO test3(a3) VALUES (NULL), (NULL), (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);//開始測試INSERT INTO test1 VALUES (1), (3), (1), (7), (1), (8), (4), (4);

SHOW TRIGGERS /G; //查看所有SELECT * FROM information_schema.TRIGGERS where TRIGGER_NAME = 'testref';

DROP TRIGGER testref;

CREATE TABLE persons (name VARCHAR(40), num int);

CREATE TABLE sales (name VARCHAR(40), sum int);

CREATE TRIGGER num_sum AFTER INSERT ON personsFOR EACH ROW INSERT INTO sales VALUES (NEW.name,7*NEW.num);

INSERT INTO persons VALUES ('xiaoxiao',20),('xiaohua',69);SELECT * FROM persons;SELECT *FROM sales;