多子句查询

-- 多子句查询顺序
SELECT column1, column2,... FROM mytable
	GROUP BY columnx
	HAVING conditionx
	ORDER BY columnx
	LIMIT startx, rowsx;

-- 统计各个部门平均工资，并且大于1000， 并且按照最低工资从高到低排序，取出前两条记录
SELECT AVG(sal) AS avg_sal, deptno
FROM emp
GROUP BY deptno
HAVING avg_sal > 1000
ORDER BY avg_sal DESC
LIMIT 0, 2