SELECT JOB, AVG(SAL) FROM EMP GROUP BY JOB

SELECT DEPTNO, AVG(SAL) FROM EMP GROUP BY DEPTNO HAVING COUNT(*)>=3

1)
SELECT DEPTNO, JOB, AVG(SAL)AS MESOS_MISTHOS FROM EMP GROUP BY DEPTNO, JOB ORDER BY DEPTNO

2)
SELECT JOB, MAX(SAL)AS MAX_MISTHOS FROM EMP GROUP BY JOB

3)
SELECT JOB, MAX(SAL)AS MAX_MISTHOS FROM EMP GROUP BY JOB HAVING MAX(SAL)>=3000

4)
SELECT JOB, MAX(SAL)AS MAX_MISTHOS, MIN(SAL) AS MIN_MISTHOS, AVG(SAL) AS AVG_MISTHOS FROM EMP GROUP BY JOB

5)


6)
SELECT JOB, COUNT(JOB) AS ARITHMOS FROM EMP GROUP BY JOB HAVING JOB='MANAGER'

7)
SELECT DEPTNO, COUNT(JOB) AS ARITHMOS FROM EMP GROUP BY DEPTNO HAVING COUNT(JOB)>3