Adv Database Management: SQL Group functions

Please note that the following blog post provides a summary view for what you need to get done (left column) and quick examples that illustrate how to do it in SQL (right column with SQL code in red). For more information please see the resources below:

AVG, COUNT, MAX, MIN, STDDEV, SUM, VARIANCE
SELECT AVG(sal), MAX(sal), MIN(sal), SUM(sal)
  FROM emp
  WHERE jobs LIKE ā€˜Sales%ā€™
COUNT
SELECT COUNT(*)
  FROM emp
  WHERE deptno = 30
Group By
SELECT deptno, AVG(sal)
  FROM emp
  GROUP BY deptno
Rollup and cube
SELECT   deptno, MAX(sal)
  FROM     emp
  GROUP BY deptno WITH ROLLUP [CUBE]
Having
SELECT   deptno, MAX(sal)
  FROM     emp
  GROUP BY deptno
  HAVING max(sal)>2900