2012-01-04 59 views
25

我正在为SUM上的多个IF条件构建查询。我在SUM上遇到了多个IF条件问题。带IF条件的MYSQL求和查询

下面是该查询:

SELECT SUM(`totalamount`) AS Total, 
SUM(`PayPalFee`) AS Fees, 
DATE(`TransactionDate`) AS `Day`, 
SUM(IF(PaymentType = "paypal", 1,0)) AS Paypal, 
SUM(IF(PaymentType = "check", 1,0)) AS Checks, 
SUM(IF(PaymentType = "credit card", 1,0)) AS CreditCard, 
COUNT(*) AS Entries 
FROM my_table 
WHERE TransactionDate between '2011-05-05' AND '2012-01-30' 
GROUP BY day 
ORDER BY `day` ASC 

此查询的工作就好了。

当我尝试添加以下条件求和声明:

SUM('TotalAmount'(PaymentType = "credit card", 1,0)) AS CreditCardTotal, 

此条件IF语句失败了。

我有一个名为'TotalAmount'的列和一个名为'PaymentType'的列我期待每天创建信用卡交易的SUM,每天支票交易的总和,PayPal的SUM每天的交易。 我试图创建一个子查询,但是这会返回整个TotalAmount列的值,而不是按天细分。

回答

62

尝试以这种方式CASE

SUM(CASE WHEN PaymentType = "credit card" THEN TotalAmount ELSE 0 END) AS CreditCardTotal, 

应该给你在找什么...

+0

太棒了!谢谢,我不能接受,但我会。 – 2012-01-04 18:40:50

+0

@aleroot'SUM(CASE WHEN .. THEN .. ELSE .. END)'和'SUM(IF(..,..,..))'之间有什么区别,当我只想检查一个条件如果一些布尔字段是1)?我的意思是,哪一个应该更快? – NHG 2014-02-10 13:36:53

+1

可以这样做,如果例如:SUM(IF(PaymentType =“creditcard”,TotalAmount,0)AS CreditCardTotal,' – George 2014-06-05 14:34:08

34

这个怎么样?

SUM(IF(PaymentType = "credit card", totalamount, 0)) AS CreditCardTotal