数据库触发器实例：学生选课成绩与学生情况表关联更新

(1)

CREATE TRIGGER tri_ins_xscj AFTER INSERT ON xscj FOR EACH ROW UPDATE xsqk SET zxf = zxf + NEW.xf WHERE xsqk.xh = NEW.xh;

(2)

CREATE TRIGGER tri_delete_xskc AFTER DELETE ON xskc FOR EACH ROW DELETE FROM xscj WHERE xscj.kh = OLD.kh;

(3)

CREATE TRIGGER tri_update_xskc AFTER UPDATE ON xskc FOR EACH ROW UPDATE xscj SET kh = NEW.kh WHERE xscj.kh = OLD.kh;