MySQL使用父键更新外键字段值

Question

in my database there is table name session and session_id is the primary key of that. and there is member table and member_id is the primary key. also there is relationship between two tables. session_id is the foreign key of member table. I want to update member_id with the same value of session_id while insert value into session table. anyone can help me with this??

Answer 1

You can use a MySQL trigger to accomplish this:

CREATE TRIGGER update_trigger
AFTER INSERT ON session FOR EACH ROW
BEGIN
    UPDATE member
    SET member_id = NEW.session_id
END;