[001]tk的一道题

显示全部楼层 · 2005-10-30 17:05:33

Exhibit button and examine the employee table.
ID NO LAST_NAME FIRST_NAME SALARY DEPT_NO
7 Brown
Terry
30000 255
6 WargnerJulie
233
4southall
david
25000 102
3chiazza
mike
50000
2limber
john
32000 145
5goldbergKelvin
233
1lomberg susan
55000
8oliver
tracey
145
You attempt to query the database with this command:
SELECT dept_no,last_name,SUM(salary)
FROM employee
WHERE salary<50000
GROUP BY dept_no
ORDER BY last_name;
Which clause causes an error?
A. FROM employee.
B. WHERE salary<50000.
C. GROUP BY dept_no.
D. ORDER BY last_name;
我认为没有正确的答案,因为使用group函数,根本不能显示last_name列.我做过试验,只要不选择last_name,再把order by last_name改为order
by dept_no就正确.如果强行选择就是D,有考过的高人明确一下答案吗?

千问 · 2005-10-30 17:05:33

选 C
SELECT dept_no,last_name,SUM(salary)
与
GROUP BY dept_no
导致结果集冲突根据语法解释的顺序,选C

千问 · 2005-10-30 17:05:33

I agree with knight_li

千问 · 2005-10-30 17:05:33

将SELECT dept_no,last_name,SUM(salary) 改为
SELECT dept_no,SUM(salary),再将order by last_name改为
order by dept_no.那么sql语句就对了,可以处正确的结果.
所以在选项中选择D.
如果不修改SELECT dept_no,last_name,SUM(salary),就是
改GROUP BY dept_no也得不到结果集

千问 · 2005-10-30 17:05:33

The EMP table contains columns to hold the birthdate and the hire date of theemployees. Both of these columns are defined with date as their data type. You wantto insert a row with the details of the employee Smith who was born in 1944 and hiredin 2004.
Which statement will ensure that values are inserted into the table in the correctcentury?
A. INSERT INTO EMP(empno,ename,birthdate,hiredate)
VALUES(EMPNO_SEQ.NEXTVAL, ‘Smith’, ‘12-dec-44’,
‘10-jun-04’ )
B. INSERT INTO EMP(empno,ename,birthdate,hiredate)
VALUES(EMPNO_SEQ.NEXTVAL, ‘Smith’,
TO_DATE(‘12-dec-44’, ‘DD-MON-RR’),
TO_DATE(‘10-jun-04’, ‘DD-MON-RR’));
C. INSERT INTO EMP(empno,ename,birthdate,hiredate)
VALUES(EMPNO_SEQ.NEXTVAL, ‘Smith’,
TO_DATE(‘12-dec-44’, ‘DD-MON-YY’),
TO_DATE(‘10-jun-04’, ‘DD-MON-YY’));
D. INSERT INTO EMP(empno,ename,birthdate,hiredate)
VALUES(EMPNO_SEQ.NEXTVAL, ‘Smith’,
TO_DATE(‘12-dec-44’, ‘DD-MON-YY’),
TO_DATE(‘10-jun-04’, ‘DD-MON-YY’));
请问有正确答案吗?
好像没有正确答案

千问 · 2005-10-30 17:05:33

答案c,d不是一样的吗？还是我没看清

千问 · 2005-10-30 17:05:33

我考的时候好像还有这道题，不过备选答案的CD不一样。
TK还是很有一些错误的。