IN/NOT IN with a Multiple-Row Subquery

CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
                  ENAME VARCHAR2(10),
                  JOB VARCHAR2(9),
                  SAL NUMBER(7, 2),
                  DEPTNO NUMBER(2));

INSERT INTO EMP VALUES (1, 'SMITH', 'CLERK',     800,    20);
INSERT INTO EMP VALUES (2, 'ALLEN', 'SALESMAN', 1600,    30);
INSERT INTO EMP VALUES (3, 'WARD',  'SALESMAN', 1250,    30);
INSERT INTO EMP VALUES (4, 'JONES', 'MANAGER',  2975,    20);
INSERT INTO EMP VALUES (5, 'MARTIN','SALESMAN', 1250,    30);
INSERT INTO EMP VALUES (6, 'BLAKE', 'MANAGER',  2850,    30);
INSERT INTO EMP VALUES (7, 'CLARK', 'MANAGER',  2850,    10);
INSERT INTO EMP VALUES (8, 'SCOTT', 'ANALYST',  3000,    20);
INSERT INTO EMP VALUES (9, 'KING',  'PRESIDENT',3000,    10);
INSERT INTO EMP VALUES (10,'TURNER','SALESMAN', 1500,    30);
INSERT INTO EMP VALUES (11,'ADAMS', 'CLERK',    1500,    20);



SQL> SELECT empno, ename FROM emp WHERE empno IN
  2  (SELECT empno FROM emp WHERE ename LIKE '%E%');

     EMPNO ENAME
---------- ----------
         2 ALLEN
         4 JONES
         6 BLAKE
        10 TURNER

SQL>
SQL> SELECT empno, ename FROM emp WHERE empno NOT IN
  2  (SELECT empno FROM emp WHERE ename LIKE '%E%');

     EMPNO ENAME
---------- ----------
         5 MARTIN
         8 SCOTT
         3 WARD
         1 SMITH
        11 ADAMS
         7 CLARK
         9 KING

7 rows selected.

SQL>