取消票务.txt

这是一个飞机订票查询系统

CREATE TRIGGER 取消定票 ON  订票
AFTER DELETE 
AS BEGIN
 
IF((SELECT 舱位类型 FROM deleted )='A')   
UPDATE 航班
SET   经济舱剩余票数=经济舱剩余票数+(SELECT 张数 FROM deleted )
WHERE 航班编号=(select 航班编号 from deleted )AND 登机日期=(select 登机日期 from deleted )

ELSE IF((SELECT 舱位类型 FROM deleted  )='B')
UPDATE 航班
SET   头等舱剩余票数=头等舱剩余票数+(SELECT 张数 FROM deleted )
WHERE 航班编号=(select 航班编号 from deleted )AND 登机日期=(select 登机日期 from deleted )


END;