创建触发器MySQL以更新employee表中的薪水

Question

如何创建触发MySQL来更新员工表中的工资并将工资栏中的旧值替换为旧工资栏？

Answer 1

请参阅CREATE TRIGGER Syntax：

create trigger salary_trigger
    before update on employee
    for each row begin
        if new.salary != old.salary then
            set new.old_salary = old.salary
        end if;
    end;