涉及到的表结构如下: Teacher(TNO,Tname,Tsex,Tnation,Tjobtitle,TID),各字段的含义依次是教师编号,姓名,性别,民族,职称,身份证号; Courses(CNO,Cname),各字段含义为课程号,课程名; Allocate(ID,TNO,CNO,Ctime),各字段含义为教师编号,课程号,课时数。编写一数据库触发器,当任何时候Teacher表中的某个教师编号TNO更新时,该触发器将Allocate表中相应的教师编号TNO进行级联更新。
正确答案:
Create or replace trigger mytrigger
After update onTeacher.TNO
For each row
Begin
Update Allocate.TNO set TNO=:NEW.TNO
Where TNO=:OLD.TNO
After update onTeacher.TNO
For each row
Begin
Update Allocate.TNO set TNO=:NEW.TNO
Where TNO=:OLD.TNO
答案解析:有

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