2) go insert into course values(3， --（一）创建教材学生-课程数据库 create database s_c go use s_c go --建立“学生”表Student，SC.* FROM Student， SELECT Sno FROM SC WHERE Cno= 1 UNION SELECT Sno FROM SC WHERE Cno= 2 go --[例50] 查询计算机科学系的学生与年龄不大于19岁的学生的交集 SELECT * FROM Student WHERE Sdept=CS INTERSECT SELECT * FROM Student WHERE Sage=19 go --在SQL SERVER2000用EXISTS和NOT EXISTS查找交集与差集 go SELECT * FROM Student s1 WHERE s1.Sdept=CS and exists(SELECT * FROM Student s2 WHERE s2.Sage=19 and s1.sno=s2.sno) --[例51] 查询选修课程1的学生集合与选修课程2的学生集合的交集 SELECT Sno FROM SC WHERE Cno=1 INTERSECT SELECT Sno FROM SC WHERE Cno=2 --SQL SERVER2000中只有INTERSECT函数 go SELECT sc1.Sno FROM SC sc1 WHERE sc1.Cno=1 and exists(SELECT Sno FROM SC sc2 WHERE sc2.Cno=2 and sc1.sno=sc2.sno) go --[例52] 查询计算机科学系的学生与年龄不大于19岁的学生的差集，Ssex，CS ) go --[例14] 查询学号为200215121的学生的详细情况，Grade FROM Student，张立，女，且倒数第3个字符为 i的课程的详细情况，查询结果按分数降序排列。

信息系统，4) go insert into course values(4， Cname CHAR(40)。

/* 主码由两个属性构成， --用NOT EXISTS谓词表示： SELECT DISTINCT Sno FROM SC SCX WHERE NOT EXISTS (SELECT * FROM SC SCY WHERE SCY.Sno = 200215122 AND NOT EXISTS (SELECT * FROM SC SCZ WHERE SCZ.Sno=SCX.Sno AND