cancel_book_tigger.sql

该票务系统包括的功能有网上订票、历史订阅纪录查询、近期上映影片推荐和查询和统计报表功能。系统面向两种用户：影院工作人员可以添加上映影片、安排影片上映场次、查询订票情况和查看统计报表功能；注册用户通过自

create or replace trigger cancel_book_tigger before delete on bookRecord
referencing old as old
for each row
begin
	update customer
	set money = money + :old.sell_prize
	where customer_id = :old.customer_id ;
end;