Logical operator AND, OR, NOT

The logical operators limits rows based on logical conditions. The logical operators are:

Operator	Description
x AND y	Returns true when both x and y are true
x OR y	Returns true when either x or y is true
NOT x	Returns true if x is false, and returns false if x is true

Using AND:

CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
                      ENAME VARCHAR2(10),
                      HIREDATE DATE);

INSERT INTO EMP VALUES (1,    NULL, TO_DATE('17-DEC-1980', 'DD-MON-YYYY'));
INSERT INTO EMP VALUES (2, 'ALLEN', TO_DATE('20-FEB-1981', 'DD-MON-YYYY'));
INSERT INTO EMP VALUES (3, 'WARD',  TO_DATE('22-FEB-1981', 'DD-MON-YYYY'));
INSERT INTO EMP VALUES (4, 'JONES', TO_DATE('2-APR-1981',  'DD-MON-YYYY'));
INSERT INTO EMP VALUES (5, 'MARTIN',TO_DATE('28-SEP-1981', 'DD-MON-YYYY'));


SQL> SELECT *
  2  FROM emp
  3  WHERE empno > 1
  4  AND ENAME ='JONES' ;

     EMPNO ENAME      HIREDATE
---------- ---------- ---------
         4 JONES      02-APR-81

SQL>
SQL>
SQL>

Using OR operator :

SQL> SELECT *
  2  FROM emp
  3  WHERE empno > 1
  4  OR ename = 'JONES';

     EMPNO ENAME      HIREDATE
---------- ---------- ---------
         2 ALLEN      20-FEB-81
         3 WARD       22-FEB-81
         4 JONES      02-APR-81
         5 MARTIN     28-SEP-81

SQL>