问答题 declare @a char(8) set @a="计算机" select计算机专业人数=count(*) from students where left(专业,3)=@a

问答题 declare @a numeric(5,2),@b numeric(5,2) set @a=(select max(成绩) from score) set @b=(select min(成绩) from score) print @a-@b

问答题 DECLARE @MyNO CHAR(8) SET @MyNO="20030001" IF (SELECT专业 FROM Students WHERE 学号=@MyNO)="计算机软件" BEGIN SELECT AVG(成绩) AS 平均成绩 FROM Score WHERE学号=@MyNO END ELSE PRINT "学号为" +@MyNO+"的学生不存在或不属于软件专业" GO