Question

DECLARE **cusname** varchar;

IF(New.BecomeVolunteer = 'Yes') 
THEN 
SELECT CusName INTO cusname FROM customer WHERE CusID = NEW.CusID;

INSERT INTO staff (StaffName, StaffTel, StaffDOB, Availability, Duties, [enter image description here][1]StaffType)
VALUES
(**cusname**, '07589634598', '1965-05-13', 'Tue,Wed,SatPM','Collecting Tickets,Ushering Customers to Seats,Looking after the Artists', 'Volunteer');
END IF

我有一个表职员，我想从“客户”表中获取“ CusName”并将其设置为变量“ cusname”。然后，我想在我的Insert语句中将该变量用作“ StaffName”属性的值

我对触发器的使用还不多，但是我了解使简单语句起作用的基本语法，但是该语句不断出现错误。如果有人可以帮助我弄清楚这里出了什么问题，我将不胜感激。

IF(New.BecomeVolunteer = 'Yes') 
THEN 
INSERT INTO staff (StaffName, StaffTel, StaffDOB, Availability, Duties, StaffType)
VALUES
('Jaamees', '07589634598', '1965-05-13', 'Tue,Wed,SatPM','Collecting Tickets,Ushering Customers to Seats,Looking after the Artists', 'Volunteer');
END IF

下面的语句工作得很好，但是上面的语句却不行（当我想添加变量时）。

Answer 1

IF默认情况下仅使用一条语句。如果要在IF中执行多个语句，请使用BEGIN...END：

IF (New.BecomeVolunteer = 'Yes') 
BEGIN
    SELECT CusName INTO cusname FROM customer WHERE CusID = NEW.CusID;
    INSERT INTO staff (StaffName, StaffTel, StaffDOB, Availability, Duties, StaffType)
    VALUES
        (cusname, '07589634598', '1965-05-13', 'Tue,Wed,SatPM',
        'Collecting Tickets,Ushering Customers to Seats,Looking after the Artists',
        'Volunteer');
END;

Answer 2

您可以在一条语句中完成所有操作：

IF (New.BecomeVolunteer = 'Yes') THEN 
    INSERT INTO staff (StaffName, StaffTel, StaffDOB, Availability, Duties, StaffType)
        SELECT c.cusname, '07589634598', '1965-05-13', 'Tue,Wed,SatPM', 'Collecting Tickets,Ushering Customers to Seats,Looking after the Artists', 'Volunteer')
        FROM customer c
        WHERE c.CustId = NEW.CusID

而且，您甚至可以删除IF：

    INSERT INTO staff (StaffName, StaffTel, StaffDOB, Availability, Duties, StaffType)
        SELECT c.cusname, '07589634598', '1965-05-13', 'Tue,Wed,SatPM', 'Collecting Tickets,Ushering Customers to Seats,Looking after the Artists', 'Volunteer')
        FROM customer c
        WHERE c.CustId = NEW.CusID AND
              New.BecomeVolunteer = 'Yes';

sql触发器的If语句中可以有多个查询语句吗？

2 个答案: