Oracle OR

 如果想在emp table 內找job 為MANAGER 或 ANALYST的資料要怎麼做呢?

如果使用以下query:

SELECT *

FROM emp

WHERE job = 'MANAGER'

AND job = 'ANALYST'

會直接找不到結果

這時候就該使用or來完成

query:

SELECT *

FROM emp

WHERE job = 'MANAGER'

OR job = 'ANALYST'

EMPNO	ENAME	JOB	MGR	HIREDATE	SAL	COMM	DEPTNO
7698	BLAKE	MANAGER	7839	1981/05/01	2850	-	30
7782	CLARK	MANAGER	7839	1981/06/09	2450	-	10
7566	JONES	MANAGER	7839	1981/04/02	2975	-	20
7788	SCOTT	ANALYST	7566	1982/12/09	3000	-	20
7902	FORD	ANALYST	7566	1981/12/03	3000	-	20

如果題目如下:

-- Get the names of those employees that are not managers nor salesmen and have a salary greater than or equal to 2000 

 query:

SELECT ENAME FROM EMP

WHERE JOB != 'MANAGER'

AND JOB != 'SALESMAN'

AND SAL >= 2000

這時候就應該要用and不能用or