SQL HAVING 實例教程
HAVING
在聽取HAVING添加到SQL ,因為在哪裡關鍵字不能使用聚合函數。
有語法的SQL
SELECT column_name, aggregate_function(column_name) FROM table_name WHERE column_name operator value GROUP BY column_name HAVING aggregate_function(column_name) operator value
下面我們來看看HAVING 一個例子吧.
_Id OrderDate OrderPrice Customer 12008/11/121000Hansen22008/10/231600Nilsen32008/09/02700Hansen42008/09/03300Hansen52008/08/302000Jensen62008/10/04100Nilsen
現在,我們要尋找是否有任何的客戶有秩序的總額小於2000年。
我們使用下面的SQL語句:
SELECT Customer,SUM(OrderPrice) FROM Orders GROUP BY Customer HAVING SUM(OrderPrice)<2000Customer SUM(OrderPrice) Nilsen1700現在,我們要尋找的客戶,如果“漢森”或“詹森”有秩序的總額超過1500 。
我們添加一個WHERE子句普通的SQL語句:
SELECT Customer,SUM(OrderPrice) FROM Orders WHERE Customer='Hansen' OR Customer='Jensen' GROUP BY Customer HAVING SUM(OrderPrice)>1500結果為.Customer SUM(OrderPrice) Hansen2000Jensen2000