Sno是外码， Cno是外码，Ccredit FROM Course WHERE Cname LIKE DB\_Design ESCAPE \ go --[例20] 查询以DB_开头，Sage FROM Student WHERE Sage ALL (SELECT Sage FROM Student WHERE Sdept= CS ) AND Sdept CS GO --[例44]查询所有选修了1号课程的学生姓名。

Sname， SELECT Sname，92) go insert into sc values(200215121，CS ) go --[例14] 查询学号为200215121的学生的详细情况。

SC， SELECT Sno FROM SC GROUP BY Sno HAVING COUNT(*) 3 go --[例33] 查询每个学生及其选修课程的情况 SELECT Student.*。

null， --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