外联接运算对悬浮行的处理有三种方式：左外联接，右外联接，全外联接，三种方式都要首先计算内联接，然后再在内联接的结果中加上相应的左（右、左和右）表中的悬浮行。

此题为判断题(对，错)。

歌曲《健康歌》中，左三圈，右三圈，脖子扭扭的下一句是什么?

此题为判断题(对，错)。

  A．跑  B．刻  C．精

  D．迢  E．相

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;

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;