Using a function as a query date range criteria

Generally, I will use functions to pass variables to queries.

However, I am having a unique problem (or senior moment <grin>) and the string that I am passing to the query is resulting a "type mismatch" error when the query executes.

Here is my function:
Public Function StudyDateRange() As String
Dim strTheString As String
Dim strTheStartDate As String
Dim strTheEndDate As String
    strTheStartDate = DLookup("dteStudyStartDate", "tblCF_StudyDateRange", True)
    strTheEndDate = DLookup("dteStudyEndDate", "tblCF_StudyDateRange", True)
    strTheString = "Between #" & strTheStartDate & "# And #" & strTheEndDate & "# Or Is Null"
    StudyDateRange = strTheString
End Function

In the query criteria of a date filed, I coded: StudyDateRange()

What am I doing wrong?

Lenny Gray
LVL 10
Who is Participating?
peter57rConnect With a Mentor Commented:
That's not my solution.
My solution was to use the expression in the criteria cell - not to assign it via a string.
Your test (DLOOKUP) is asking if dteStudyStartDate in tblCF_StudyDateRange is True.

I think you may be looking to use the dmax() and dmin() funciton.
The criteria is being interpreted as a literal string, not as an expression.
I'm not sure how you would convert it into a valid criteria expression using a function.
Have you tried to use:

Between  DLookup("dteStudyStartDate", "tblCF_StudyDateRange") and
DLookup("dteStudyEndDate", "tblCF_StudyDateRange")

Cloud Class® Course: CompTIA Healthcare IT Tech

This course will help prep you to earn the CompTIA Healthcare IT Technician certification showing that you have the knowledge and skills needed to succeed in installing, managing, and troubleshooting IT systems in medical and clinical settings.

DimitrisSenior Solution ArchitectCommented:
I think that in the place holder " ##########" you need to add the column name

 strTheString = "Between #" & strTheStartDate & "# And #" & strTheEndDate & "# Or ########## Is Null"
LennyGrayAuthor Commented:
Brandon -

The table is a single-record table. So the criteria being forced to True is valid.

Peter57r -

I tried your solution to no avail. Even after I changed it to:    

strTheString = "Between " & DLookup("dteStudyStartDate", "tblCF_StudyDateRange") & " and " & DLookup("dteStudyEndDate", "tblCF_StudyDateRange")
LennyGrayAuthor Commented:
Oh, thanks Peter, but I know that I could do that already.

I am looking for a generic (function-based) criteria that I can use at will.

The user defines a study period, which is a date range that I apply to pre-written queries. By passing a function as the criteria, I am able to keep the same query and let it be altered by the function values at runtime.

LennyGrayAuthor Commented:
Thanks, Peter. I misunderstood. When I applied your approach, it gave me the flexibility that I was seeking with the function.

Sorry for the mis-read on my part!
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.