触发器：关联删除

-- 5. 在tb_student表上创建1个触发器，当用户删除学生记录时将与之关联的tb_score表中的记录删除。本上。
-- 1) 创建触发器。
-- 2) 插入测试记录到tb_student和tb_score表中。(用于测试触发器是否正常工作)
-- 3) 删除测试记录验证触发器是否正常工作。
SELECT * FROM tb_score;
SELECT * FROM tb_student;


delimiter //
CREATE TRIGGER  zuoyu11
BEFORE
DELETE 
ON tb_student 
FOR EACH ROW
BEGIN
 DELETE FROM tb_score WHERE student_no = old.student_no;
END //
delimiter;


INSERT into tb_score VALUES(NULL,'s12',3,88, '2010-10-10');
INSERT into tb_student VALUES('s12','123456','ww','男',1,'1234567','学生宿舍','1985-10-10','1234');

Show triggers;

DELETE FROM tb_student WHERE student_no='s11';