题目内容

基于教材上的选课表SC，使用嵌套查询查找所有超过所选课程平均分的学生选课记录，正确的SQL语句是________。

A. SELECTSno, Cno, Grade FROMSC SC1WHERE Grade>(SELECT AVG(Grade) FROMSC SC2);
B. SELECTSno, Cno, Grade FROMSC SC1WHERE Grade>(SELECT AVG(Grade) FROMSC SC2 WHERE SC2.Cno=SC1.Cno);
C. SELECTSno, Cno, Grade FROMSC SC1WHERE Grade>(SELECT AVG(Grade) FROMSC SC2 GROUP BY SC2.Cno);
D. SELECTSno, Cno, Grade FROMSC SC1WHERE AVG(Grade)>(SELECT Grade FROMSC SC2 WHERE SC2.Cno=SC1.Cno);

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现有学生关系表S(sno，sname，ssex，sage），查找年龄比某个女生小的男生信息，对应的SQL语句是________。

A. select * fromSwhere ssex='男' and sage in(select sage from S where ssex='女');
B. select * fromSwhere ssex='男' and sage<(select sage from S where ssex='女');
C. select * fromSwhere ssex='男' and sage D. select * fromSwhere ssex='男' and sage

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现有学生关系表S(sno，sname，ssex，sage）和选修关系表SC(sno, cname, grade)，查找没有选修"数据库"课程的学生个人信息，对应的SQL语句是________。

A. select*fromS where exists(select * from SC where SC.sno=S.sno and SC.cname<>'数据库 );
B. select*fromS where exists(select * from SC where SC.sno<>S.sno and SC.cname='数据库 );
C. select*fromS where not exists(select * from SC where SC.sno=S.sno and SC.cname<>'数据库 );
D. select*fromS where not exists(select * from SC where SC.sno=S.sno and SC.cname='数据库 );

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现有学生关系表S(sno，sname，ssex，sage），查找比所有"张三"年龄大的男生信息，下列选项中正确的SQL语句是________。

A. select * fromSwhere ssex='男' and sage>SOME(select sage from S where sname='张三);
B. select * fromSwhere ssex='男' and sage>ALL(select sage from S where sname='张三);
C. select * fromSwhere ssex='男' and sage>(select max(sage) from S where sname='张三);
D. select * fromSwhere ssex='男' and sage>(select min(sage) from S where sname='张三);

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Listen to a dialogue and decode the message by finding out the correct choices in brackets according to what you have heard.When Bob knows that Jack and some of his friends are having a 1 (meeting, party, game) at Emily’s house, he says he would like to 2 (join, see, miss) them. He doesn’t know where Emily lives, so he is asking for 3 (information, decisions, directions). He is told that Emily’s house is quite 4 (close, distant, near) and it will take him about 5 (five, fifteen, fifty) minutes to get there. He has to take a left turning at the 6 (traffic lights, flyover, crossroads) on Main Street and then a right turning at the 7 (police station, petrol station, railway station). He has to go down the road until he comes to a 8 (fork, sign, square) and turn right. About 9 (one, two, three) hundred meters up the right road he will see a 10 (one-story, two-story, three-story) building on the right.

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