2020 数据库应用(江汉大学)1450753650 最新满分章节测试答案

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本课程起止时间为:2020-02-17到2020-07-15
本篇答案更新状态:已完结

第三章 PG数据定义与操作（下） 第三章 PG数据定义与操作（下）单元测验（B）

1、 问题:检索全部考生都报考的试卷号和试卷名，查询语句就可以写成（ ）。
选项：
A:SELECT eid,ename FROM exampaperWHERE eid in (SELECT eid FROM eeexam GROUP BY eid HAVING COUNT(eeid)=(SELECT COUNT(eeid) FROM examinee) );
B:SELECT eid,ename FROM exampaper WHERE NOT EXIST (SELECT * FROM examinee WHERE NOT EXIST (SELECT * FROM eeexam WHERE examinee.eeid=eeid and exampaper.eid=eid) );
C:SELECT eid，ename FROM exampaper WHERE NOT EXISTS（（SELECT eeid FROM examinee） EXCEPT（SELECT eeid FROM eeexam WHERE exampaper.eid=eid））;
D:SELECT FROM examineeORDER BY eeidlimit 2 offset ((SELECT count() FROM examinee)-2);
E:SELECT FROM examineeORDER BY eeidLIMIT (SELECT COUNT() FROM eeexam);
F:SELECT FROM departmentWHERE EXISTS (SELECT * FROM examiner WHERE erdepa=department. dname AND eid= ername= ‘范冰冰’);
G:SELECT eedepa, AVG(eeage)FROM examineeGROUP BY eedepaHAVING eedepa IN (SELECT eedepa FROM examinee WHERE eename=’刘诗诗’);
H:SELECT dname, (SELECT COUNT() FROM examiner WHERE department.dname = examiner.erdepa)FROM department;
I:SELECT (SELECT eedepa FROM examinee WHERE eeexam.eeid=examinee.eeid), AVG(achieve)FROM eeexamGROUP BY (SELECT eedepa FROM examinee WHERE eeexam.eeid=examinee.eeid);
答案: 【SELECT eid,ename FROM exampaperWHERE eid in (SELECT eid FROM eeexam GROUP BY eid HAVING COUNT(eeid)=(SELECT COUNT(eeid) FROM examinee) );;
SELECT eid,ename FROM exampaper WHERE NOT EXIST (SELECT * FROM examinee WHERE NOT EXIST (SELECT * FROM eeexam WHERE examinee.eeid=eeid and exampaper.eid=eid) );;
SELECT eid，ename FROM exampaper WHERE NOT EXISTS（（SELECT eeid FROM examinee） EXCEPT（SELECT eeid FROM eeexam WHERE exampaper.eid=eid））;】

2、 问题:在写嵌套查询语句时，一个查询块可以嵌套在另一个查询块的（ ）子句中。
选项：
A:SELECT
B:FROM
C:WHERE
D:GROUP BY
E:HAVING
F:ORDER BY
G:LIMIT
H:OFFSET
I:WITH
J:FOR
K:WHILE
L:INDEX
M:CREATE
答案: 【SELECT;
FROM;
WHERE;
GROUP BY;
HAVING;
ORDER BY;
LIMIT;
OFFSET;
WITH】

3、 问题:查询平均成绩良好，也就是≥80分的考生人数，查询语句就可以写成（ ）。
选项：
A:WITH avgach (eeid,avgachieve) AS ( SELECT eeid,AVG(achieve) FROM eeexam GROUP BY eeid )SELECT COUNT() FROM avgachWHERE avgachieve>=80;
B:WITH avgach (eeid,avgachieve) ( SELECT eeid,AVG(achieve) FROM eeexam GROUP BY eeid )SELECT COUNT() FROM avgachWHERE avgachieve>=80;
C:SELECT COUNT() FROM (SELECT eeid,avg(achieve) FROM eeexam GROUP BY eeid )AS avgach (eeid,avgachieve) WHERE avgachieve>=80;
D:SELECT COUNT() FROM (SELECT eeid,avg(achieve) FROM eeexam GROUP BY eeid ) avgach (eeid,avgachieve) WHERE avgachieve>=80;
E:SELECT dname, (SELECT COUNT() FROM examiner WHERE department.dname = examiner.erdepa)FROM departmentWHERE avgachieve>=80;
F:SELECT * FROM erexam NATURAL LEFT OUTER JOIN exampaper;
答案: 【WITH avgach (eeid,avgachieve) AS ( SELECT eeid,AVG(achieve) FROM eeexam GROUP BY eeid )SELECT COUNT() FROM avgachWHERE avgachieve>=80;;
SELECT COUNT() FROM (SELECT eeid,avg(achieve) FROM eeexam GROUP BY eeid )AS avgach (eeid,avgachieve) WHERE avgachieve>=80;;
SELECT COUNT() FROM (SELECT eeid,avg(achieve) FROM eeexam GROUP BY eeid ) avgach (eeid,avgachieve) WHERE avgachieve>=80;】

4、 问题:查询各考生及其报考的试卷，查询语句就可以写成（ ）。
选项：
A:SELECT FROM examinee，eeexam WHERE examinee.eeid = eeexam.eeid；
B:SELECT FROM examinee CROSS JOIN eeexam WHERE examinee.eeid = eeexam.eeid；
C:SELECT * FROM examinee NATURAL JOIN eeexam；
D:SELECT FROM examinee JOIN eeexam USING(eeid)；
E:SELECT FROM examinee JOIN eeexam ON examinee.eeid = eeexam.eeid；
F:SELECT FROM examinee，eeexam；
G:SELECT FROM examinee CROSS JOIN eeexam；
H:SELECT FROM examinee CROSS JOIN erexam；
I:SELECT FROM examiner CROSS JOIN erexam；
J:SELECT FROM examiner，erexam
答案: 【SELECT FROM examinee，eeexam WHERE examinee.eeid = eeexam.eeid；;
SELECT FROM examinee CROSS JOIN eeexam WHERE examinee.eeid = eeexam.eeid；;
SELECT * FROM examinee NATURAL JOIN eeexam；;
SELECT FROM examinee JOIN eeexam USING(eeid)；;
SELECT *FROM examinee JOIN eeexam ON examinee.eeid = eeexam.eeid；】

5、 问题:查询表erexam和表exampaper自然左外联接，查询语句就可以写成（ ）。
选项：
A:SELECT * FROM erexam NATURAL LEFT OUTER JOIN exampaper;
B:SELECT * FROM erexam NATURAL LEFT JOIN exampaper;
C:SELECT * FROM erexam NATURAL JOIN exampaper;
D:SELECT * FROM erexam OUTER JOIN exampaper;
E:SELECT * FROM erexam NATURAL OUTER JOIN exampaper;
F:SELECT * FROM erexam LEFT OUTER JOIN exampaper;
答案: 【SELECT * FROM erexam NATURAL LEFT OUTER JOIN exampaper;;
SELECT * FROM erexam NATURAL LEFT JOIN exampaper;】

6、 问题:与“NOT IN”等价的操作符是（ ）。
选项：
A:=SOME
B:<>SOME
C:=ALL
D:<>ALL
E:!= ALL
F:=ANY
G:<>ANY
答案: 【<>ALL;
!= ALL】

7、 问题:有语句：SELECT DISTINCT eridFROM erexamWHERE erid IN ( SELECT erid FROM examiner WHERE erdepa=’IST’);与其执行结果等价的关系代数表达式是（ ）。
选项：
A:
B:
C:
D:
E:
F:
G:
H:
I:
J:
K:
答案: 【;
;
;
;
】

8、 问题:有语句：SELECT DISTINCT eridFROM erexam,examinerWHERE examiner.erid=erexam.erid AND erdepa=’IST’;与其执行结果等价的关系代数表达式是（ ）。
选项：
A:
B:
C:
D:
E:
F:
G:
H:
I:
J:
K:
答案: 【;
;
;
;
】

9、 问题:有关系代数表达式：与其执行结果等价的pgSQL语句为（ ）。
选项：
A:SELECT DISTINCT examinee.eeid,eename,eidFROM eeexam,examineeWHERE examinee.eeid=eeexam.eeid;
B:SELECT DISTINCT examinee.eeid,eename,eidFROM eeexam CROSS JOIN examineeWHERE examinee.eeid=eeexam.eeid;
C:SELECT DISTINCT eeid,eename,eidFROM eeexam NATURAL JOIN examinee;
D:SELECT DISTINCT examinee.eeid,eename,eidFROM eeexam JOIN examinee ON examinee.eeid=eeexam.eeid;
E:SELECT DISTINCT eeid,eename,eidFROM eeexam JOIN examinee USING(eeid);
F:SELECT DISTINCT examinee.eeid,eename,eidFROM eeexam,examinee;
G:SELECT DISTINCT examinee.eeid,eename,eidFROM eeexam CROSS JOIN examinee;
H:SELECT DISTINCT eeid,eename,eidFROM eeexam NATURAL JOIN examineeWHERE examinee.eeid=eeexam.eeid;
I:SELECT DISTINCT examinee.eeid,eename,eidFROM eeexam JOIN examinee WHERE examinee.eeid=eeexam.eeid;
答案: 【SELECT DISTINCT examinee.eeid,eename,eidFROM eeexam,examineeWHERE examinee.eeid=eeexam.eeid; ;
SELECT DISTINCT examinee.eeid,eename,eidFROM eeexam CROSS JOIN examineeWHERE examinee.eeid=eeexam.eeid; ;
SELECT DISTINCT eeid,eename,eidFROM eeexam NATURAL JOIN examinee;;
SELECT DISTINCT examinee.eeid,eename,eidFROM eeexam JOIN examinee ON examinee.eeid=eeexam.eeid;;
SELECT DISTINCT eeid,eename,eidFROM eeexam JOIN examinee USING(eeid);】

10、 问题:有关系代数表达式：与其执行结果等价的pgSQL语句为（ ）。
选项：
A:SELECT FROM eeexam,examineeWHERE examinee.eeid=eeexam.eeid;
B:SELECT FROM eeexam CROSS JOIN examineeWHERE examinee.eeid=eeexam.eeid;
C:SELECT FROM eeexam NATURAL JOIN examinee;
D:SELECT FROM eeexam JOIN examinee ON examinee.eeid=eeexam.eeid;
E:SELECT FROM eeexam JOIN examinee USING(eeid);
F:SELECT FROM eeexam,examinee;
G:SELECT FROM eeexam CROSS JOIN examinee;
H:SELECT FROM eeexam NATURAL JOIN examineeWHERE examinee.eeid=eeexam.eeid;
I:SELECT FROM eeexam JOIN examinee WHERE examinee.eeid=eeexam.eeid;
答案: 【SELECT FROM eeexam,examineeWHERE examinee.eeid=eeexam.eeid; ;
SELECT FROM eeexam CROSS JOIN examineeWHERE examinee.eeid=eeexam.eeid; ;
SELECT FROM eeexam JOIN examinee ON examinee.eeid=eeexam.eeid;】

11、 问题:查询块可以出现在另外一个查询中表名可以出现的任何地方。
选项：
A:正确
B:错误
答案: 【正确】

12、 问题:PG中其它子句都可以不出现，但至少要有一个SELECT子句。
选项：
A:正确
B:错误
答案: 【正确】

13、 问题:谓词EXISTS可用来测试一个集合是否有重复元组。
选项：
A:正确
B:错误
答案: 【错误】

14、 问题:有SQL语句：UPDATE examinerSET ersalary=ersalary*1.05WHERE erdepa=’信息学院’AND ersalary<（SELECT AVG（ersalary） FROM examiner）；其执行结果是为工资低于信息学院平均工资的所有考官加薪5%。

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