9、让SELECT 语句的输出结果为
- SELECT * FROM SALGRADE;
- SELECT * FROM BONUS;
- SELECT * FROM EMP;
- SELECT * FROM DEPT;
- ……
列出当前用户有多少张数据表,结果集中存在多少条记录。 |
10、判断SELECT ENAME,SAL FROM EMP WHERE SAL > '1500'是否抱错,为什么?
各试题解答如下(欢迎大家指出不同的方法或建议!):
-
- SQL> SELECT ENAME FROM SCOTT.EMP WHERE ENAME LIKE '__A%';
-
- ENAME
-
- ADAMS
- BLAKE
- CLARK
|
-
- SQL> SELECT ENAME FROM SCOTT.EMP WHERE ENAME LIKE '%A%' AND ENAME LIKE '%N%';
-
- ENAME
-
- ALLEN
- MARTIN
- WANGJING
-
- SQL> SELECT ENAME FROM SCOTT.EMP WHERE ENAME LIKE '%A%N%';
-
- ENAME
-
- ALLEN
- MARTIN
- WANGJING
|
- /*
- 佣金从大到小。
- SQL> SELECT ENAME,SAL + COMM AS WAGE,COMM
- 2 FROM SCOTT.EMP
- 3 ORDER BY WAGE,COMM DESC;
-
- ENAME WAGE COMM
-
- TURNER 1500 0.00
- WARD 1750 500.00
- ALLEN 1900 300.00
- MARTIN 2650 1400.00
- EricHu 5514 14.00
- WANGJING 5514 14.00
- huyong 5514 14.00
- SMITH
- JONES
- JAMES
- MILLER
- FORD
- ADAMS
- BLAKE
- CLARK
- SCOTT
- KING
-
- 17 rows selected
|
-
- SQL> SELECT DISTINCT JOB FROM EMP WHERE DEPTNO = 20;
-
- JOB
-
- ANALYST
- CLERK
- MANAGER
|