Trigger: MySQL implements adding or deleting a piece of data in one table and adding another table at the same time

Create a trigger , Watch student_message Start adding stu_id,id_time Field data , surface student_score Of stu_id,id_time The data of the field is also added , If the table student_message Some lines have been deleted , surface student_score Also follow the table student_message Corresponding stu_id,id_time Delete the entire row of data of the field .