Oracle试题
一、选择题
1.当你执行以下查询语句:
SELECT empno,ename
FROM emp
WHERE empno =7782 OR empno =7876;
在WHERE语句中,以下哪个操作符可以取代OR?
A. IN
B. BETWEEN ……
C. LIKE
D. <=
E. >=
Answer: A
2. 哪个实现 IF..THEN…ELSE 逻辑?
A. INITCAP()
B. REPLACE()
C. DECODE()
D. IFELSE()
Answer: C
3. 以下哪行有错?
1 SELECT deptno
2 FROM emp
3 GROUP BY deptno
4 HAVING COUNT(deptno)=
5 (SELECT max(count(deptno))
6 FROM emp
7 GROUP BY deptno);
A. Line 3
B. Line 4
C. Line 5
D. Line 7
E. 都没错.
Answer: E
4. 当一个程序执行了 SELECT...FOR UPDATE 语句, 以下哪个步骤必