SQL IF语句可能吗? [英] SQL IF statement possible?

问题描述

所以我有这个查询，如下所示:

So I have this Query as follows:

UPDATE CustomerBankInfo
SET [Money] = ([Money] - @orderValue)
WHERE CustomerBankInfo.CustomerID = (SELECT CustomerID
                                     FROM Customer
                                     WHERE FirstName = @custFName
                                     AND LastName =@custLName)

但是，如果'Money'小于0，我不希望它运行.我尝试这样做:

However I don''t want it to run if ''Money'' is less than 0. I''ve tried doing:

UPDATE CustomerBankInfo
SET [Money] = ([Money] - @orderValue)
IF [Money] > 0
WHERE CustomerBankInfo.CustomerID = (SELECT CustomerID
                                     FROM Customer
                                     WHERE FirstName = @custFName
                                     AND LastName =@custLName)

不起作用.有什么建议?谢谢.

Doesn''t work. Any suggestions? Thanks.

推荐答案

您没有提供有关表属性和变量的datatype 的足够详细信息>，让我猜想您在 [Money] 字段中使用了datatype money.如果我是对的，请尝试使用以下代码:

You didn''t provide enough detail regarding datatype of your table attributes and variable, let me guess you are using datatype money for your [Money] field. If i am right, try using the following code:

UPDATE CustomerBankInfo
SET [Money] = ([Money] - CONVERT(money,@orderValue)
WHERE CustomerBankInfo.CustomerID = (SELECT CustomerID
                                     FROM Customer
                                     WHERE FirstName = @custFName 
                                     AND LastName =@custLName) 
AND ([Money] > CONVERT(money,0))

放入AND Money > 0放入where子句中.

Put AND Money > 0 into your where clause.

正确的想法是:将您的Money条件放在WHERE子句中.

—SA

The right idea is: put your condition for Money in WHERE clause.

—SA

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