Operator | Purpose | Example |
NOT | Returns TRUE if the following condition is FALSE. Returns FALSE if it is TRUE. If it is UNKNOWN, it remains UNKNOWN. | SELECT * FROM emp WHERE NOT (job IS NULL) SELECT * FROM emp WHERE NOT (sal BETWEEN 1000 AND 2000) |
AND | Returns TRUE if both component conditions are TRUE. Returns FALSE if either is FALSE; otherwise, returns UNKNOWN. | SELECT * FROM emp WHERE job = 'CLERK' AND deptno = 10 |
OR | Returns TRUE if either component condition is TRUE. Returns FALSE if both are FALSE; otherwise, returns UNKNOWN. | SELECT * FROM emp WHERE job = 'CLERK' OR deptno = 10 |