关系代数表达式: [图] 其对应的SQL语句为()。A、SELECT...
关系代数表达式:其对应的SQL语句为()。
A、SELECT * FROM examinee;
B、SELECT DISTINCT eename,eeage,eesex FROM examinee;
C、SELECT * FROM examinee(eename,eeage,eesex);
D、SELECT eename,eeage,eesex ;
关系代数表达式:其对应的SQL语句为()。
A、SELECT * FROM examinee;
B、SELECT DISTINCT eename,eeage,eesex FROM examinee;
C、SELECT * FROM examinee(eename,eeage,eesex);
D、SELECT eename,eeage,eesex ;
第1题
关系代数表达式:其对应的SQL语句为( )。
A、SELECT eename,eeage,eesex FROM examinee WHERE eeage>=18 AND eeage<=23;<br> B、SELECT * FROM examinee WHERE eeage>=18 AND eeage<=23;<br> C、SELECT eename,eeage,eesex FROM examiner WHERE eeage>=18 AND eeage<=23;<br> D、SELECT eename,eeage,eesex FROM examinee WHERE 18<=eeage<=23;<br> E、SELECT eename,eeage,eesex FROM examinee WHERE eeage>=18 HAVING eeage<=23;<br> F、SELECT eename,eeage,eesex FROM examinee HAVING eeage>=18 AND eeage<=23;<br> G、SELECT eename,eeage,eesex FROM examinee HAVING eeage>=18 OR eeage<=23;<br> H、SELECT eename,eeage,eesex FROM examinee WHERE eeage>=18 OR eeage<=23;<br>
第2题
有关系代数表达式:与其执行结果等价的pgSQL语句为( )。
A、SELECT * FROM eeexam,examinee WHERE examinee.eeid=eeexam.eeid;
B、SELECT * FROM eeexam CROSS JOIN examinee WHERE 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 examinee WHERE examinee.eeid=eeexam.eeid;
I、SELECT * FROM eeexam JOIN examinee WHERE examinee.eeid=eeexam.eeid;
第3题
有关系代数表达式:与其执行结果等价的pgSQL语句为( )。
A、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam,examinee WHERE examinee.eeid=eeexam.eeid;
B、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam CROSS JOIN examinee WHERE examinee.eeid=eeexam.eeid;
C、SELECT DISTINCT eeid,eename,eid FROM eeexam NATURAL JOIN examinee;
D、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam JOIN examinee ON examinee.eeid=eeexam.eeid;
E、SELECT DISTINCT eeid,eename,eid FROM eeexam JOIN examinee USING(eeid);
F、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam,examinee;
G、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam CROSS JOIN examinee;
H、SELECT DISTINCT eeid,eename,eid FROM eeexam NATURAL JOIN examinee WHERE examinee.eeid=eeexam.eeid;
I、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam JOIN examinee WHERE examinee.eeid=eeexam.eeid;
第4题
有关系代数表达式:与其执行结果等价的pgSQL语句为( )。
A、SELECT * FROM eeexam,examinee WHERE examinee.eeid=eeexam.eeid;
B、SELECT * FROM eeexam CROSS JOIN examinee WHERE 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 CROSS JOIN examinee;
G、SELECT * FROM eeexam NATURAL JOIN examinee WHERE examinee.eeid=eeexam.eeid;
H、SELECT * FROM eeexam JOIN examinee WHERE examinee.eeid=eeexam.eeid;
第5题
有关系代数表达式:与其执行结果等价的pgSQL语句为( )。
A、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam,examinee WHERE examinee.eeid=eeexam.eeid;
B、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam CROSS JOIN examinee WHERE examinee.eeid=eeexam.eeid;
C、SELECT DISTINCT eeid,eename,eid FROM eeexam NATURAL JOIN examinee;
D、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam JOIN examinee ON examinee.eeid=eeexam.eeid;
E、SELECT DISTINCT eeid,eename,eid FROM eeexam JOIN examinee USING(eeid);
F、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam,examinee;
G、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam CROSS JOIN examinee;
H、SELECT DISTINCT eeid,eename,eid FROM eeexam NATURAL JOIN examinee WHERE examinee.eeid=eeexam.eeid;
I、SELECT DISTINCT examinee.eeid,eename,eid FROM eeexam JOIN examinee WHERE examinee.eeid=eeexam.eeid;
第7题
若有关系R(A,B,C,D)和S(C,D,E),则与表达式等价的SQL语句如下:SELECT(1)FROM(2)WHERE(3);
空白(1)处应选择()
A. A,B,C,D,E
B. C,D,E
C. R.A,R.B,R.C,R.D,S.E
D. R.C,R.D,S.E
第8题
若有关系R(A,B,C,D)和S(C,D,E),则与表达式等价的SQL语句如下:SELECT(1)FROM(2)WHERE(3);
空白(3)处应选择()
A. D
第9题
若有关系R(A,B,C,D)和S(C,D,E),则与表达式等价的SQL语句如下:SELECT(1)FROM(2)WHERE(3);
空白(2)处应选择()
A. R
B. S
C. R,S
D. RS
第10题
为了保护您的账号安全,请在“上学吧”公众号进行验证,点击“官网服务”-“账号验证”后输入验证码“”完成验证,验证成功后方可继续查看答案!