DEPT_NO IS NOT
SELECT DEPT.DEPT_NO, AVG (EMP.EMP_SAL)
FROM DEPT, EMP
WHERE DEPT.DEPT_NO = EMP.DEPT_NO
GROUP BY DEPT.DEPT_NO
HAVING UNIQIUE (SELECT AVG (EMP1.EMP_SAL)
FROM EMP EMP1
WHERE EMP1. DEPT_NO IS NOT NULL
GROUP BY EMP1.DEPT_NO
HAVING AVG (EMP1.EMP_SAL) = AVG (EMP.EMP_SAL));
