USE school
alter table choices drop [FK_CHOICES_STUDENTS];
alter table choices add 
CONSTRAINT [FK_CHOICES_STUDENTS] FOREIGN KEY 
	(
		[sid]
	) REFERENCES [dbo].[STUDENTS] (
		[sid]
	)on delete cascade;
delete from students where sid='800001216';
select * from stu_card;
select * from icbc_card;