我在IIf函数中是否需要两个条件? [英] Do I need both conditions in IIf function?

问题描述

我知道SQL中IIf函数的语法是

I know the syntax of the IIf function in SQL is

IIf(布尔表达式，真值，假值)

但是我刚刚找到了一个写在其中的SQL代码

But I just found a SQL Code where is written

IIf([DATE_USER_TO_SPECIALIST] Is Not Null, Year([DATE_USER_TO_SPECIALIST]) & "." & IIf(Month([DATE_USER_TO_SPECIALIST])<=9,"0","") & Month([DATE_USER_TO_SPECIALIST])) AS DATE_USER_TO_SPECIALIST_YYYYMM

它有效.但是如何?我找不到错误的值，还是不需要该错误的值?

And it works. But how? I can't find the false value, or is the false value not required?

推荐答案

Jet-SQL具有自己的内置IIF函数，可让您省略错误的部分.在这种情况下，它的作用就像您为第三个参数传递了Null值.

Jet-SQL has own build-in IIF function which allows you to omit false part. In this case it acts like you passed Null value for the third argument.

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