访问查询条件“如果选项3，则返回null”

Question

I have an Access query that looks at a Form to see which of 3 radio buttons (in a group called frmStatus) is selected. If the first is selected, the IIF returns "True", and if the second is selected, it returns "False", but if the third is selected, I want the IIF to return absolutely nothing so the criteria is, in effect, empty.

Right now, this is my criteria:

IIf([Forms]![SP_Search_Criteria]![frmStatus]=3,Like "*",IIf([Forms]![SP_Search_Criteria]![frmStatus]=1,True,False))

With the SQL for that (Disregard the Date() part -- that's for searching by age):

WHERE ((((Date()-[DoB])/365.25)>=[Forms]![SP_Search_Criteria]![txtMinAge] And ((Date()-[DoB])/365.25)<[Forms]![SP_Search_Criteria]![txtMaxAge]) AND ((StandardizedPatients.Active)=IIf([Forms]![SP_Search_Criteria]![frmStatus]=3,(StandardizedPatients.Active) Like "*",IIf([Forms]![SP_Search_Criteria]![frmStatus]=1,True,False))))

Options 1 and 2 work just fine... I can't seem to get Option 3 to work at all.

So, my question is this: What can I put in an IIF inside a Query Criteria to effectively search without a criteria?

Answer 1

我可以正常工作-我所做的只是删除了“ Like“ *””部分，所以现在WHERE看起来像这样：

WHERE ((((Date()-[DoB])/365.25)>=[Forms]![SP_Search_Criteria]![txtMinAge] And ((Date()-[DoB])/365.25)<[Forms]![SP_Search_Criteria]![txtMaxAge]) AND ((StandardizedPatients.Active)=IIf([Forms]![SP_Search_Criteria]![frmStatus]=3,(StandardizedPatients.Active),IIf([Forms]![SP_Search_Criteria]![frmStatus]=1,True,False))))