ORACLE HAVING，oraclehaving

ORACLE HAVING，oraclehaving

在 SQL 中增加 HAVING 子句原因是，WHERE 關鍵字無法與合計函數一起使用。

文法：
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

例子1：尋找訂單總金額少於 2000 的客戶

SELECT Customer,SUM(OrderPrice) FROM Orders
GROUP BY Customer
HAVING SUM(OrderPrice)<2000;

例子2：尋找客戶 "Bush" 或 "Adams" 擁有超過 1500 的訂單總金額

SELECT Customer,SUM(OrderPrice) FROM Orders
WHERE Customer='Bush' OR Customer='Adams'
GROUP BY Customer
HAVING SUM(OrderPrice)>1500;