最新国开电大《数据库应用技术》第二次形考作业答案

左外连接

右外连接

内连接

自连接

SUM(列名)

MAX(列名)

AVG(列名)

COUNT(*)

SELECT Sno, COUNT(*) FROM SC GROUP BY Sno

SELECT Sno FROM SC GROUP BY Sno WHERE COUNT(*) > 3

SELECT Sno FROM SC GROUP BY Sno HAVING COUNT(*) > 3

SELECT Sno FROM SC GROUP BY Sno

SELECT Sname, MIN(Sage) FROM Student

SELECT Sname, Sage FROM Student WHERE Sage = MIN(Sage)

SELECT TOP 1 Sname, Sage FROM Student

SELECT TOP 1 Sname, Sage FROM Student ORDER BY Sage

Case Grade

　Else  ‘不及格’

End

Case

End

Case

　Else  ‘不及格’

End

Case Grade

End

ALTER

SELECT

UPDATE

INSERT

INSERT INTO Teachers VALUES(‘T100′,’张宏’,NULL)

INSERT INTO Teachers(Tno,Tname,Age) VALUES(‘T100′,’张宏’,30)

INSERT INTO Teachers(Tno,Tname) VALUES(‘T100′,’张宏’)

INSERT INTO TeachersVALUES(‘T100′,’张宏’)

仅Student表

仅Student和SC表

仅Student和Course表

Student、SC和Course表

DELETE  FROM SC JOIN Student b ON S.Sno = b.Sno

　WHERE Sdept = ‘计算机系’

DELETE FROM SC FROM SC JOIN Student b ON SC.Sno = b.Sno

　WHERE Sdept = ‘计算机系’

DELETE FROM Student  WHERE Sdept = ‘计算机系’

DELETE FROM SC WHERE Sdept = ‘计算机系’

SELECT TOP 5 姓名, 年龄 FROM 学生表

SELECT TOP 5 姓名, 年龄 FROM 学生表 ORDER BY 年龄

SELECT TOP 5 姓名, 年龄 FROM 学生表 ORDER BY 年龄 DESC

SELECT TOP 5 WITH TIES姓名, 年龄 FROM 学生表