SQL when then 练习题

   create table TblScore
   (
   tScoreId int identity primary key not null,
   tSid int  not null,
   tEnglish int null,
   tMath int null,
   )
   go
   insert into TblScore values(1,56,100)
      insert into TblScore values(2,88,92)
	     insert into TblScore values(3,90,72)
		    insert into TblScore values(4,99,78)
			   insert into TblScore values(5,90,83)
			      insert into TblScore values(6,null,80)
			      insert into TblScore values(7,90,68)
				  insert into TblScore values(8,90,51)
				insert into TblScore values(9,40,17)
			insert into TblScore values(10,95,70)
select * from TblScore

select *,
		是否及格=case
		when [tenglish]>60 and [tmath]>60 then '及格'
		else '不及格'
		end
from TblScore