Solved

Getting DLookup to return a Null value in Access - VB6

Posted on 2006-07-18
7
445 Views
Last Modified: 2012-06-22
Hello experts,

This should be pretty easy but I cannot figure it out.  I am new to VB and having problems.

I am trying to make a form in Access that will allow the user to input their employee number into a textbox.  Once they click the button, it will look for thier name in a table and retreive their info or return a Null value if the number is not found.  I have had not problems having it find records that are there, but I cannot figure out how to make it return a Null if there is no record found.

Here is my code:

' NumberInputTxt , FirstNameTxt , and ValidTxt  are all textboxes
' identipass is the table I am looking in

' the problem is I cannot get varX to = Null.  I have also tried if varX="" which did not work


Private Sub numberinputtxt_Click()

Dim CardNumber As String
Dim varX As Variant

CardNumber = NumberInputTxt.Text

varX = DLookup("[First]", "Identipass", "[Number]= " & CardNumber)

FirstNameTxt = varX

If varX = Null Then
ValidTxt = "Null"

Else

ValidTxt = "Found"
End If

End Sub

----------------------------------------------------------

Thanks in advance!
0
Comment
Question by:paries
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 2
7 Comments
 
LVL 34

Expert Comment

by:flavo
ID: 17133256
If varX Is Null Then
ValidTxt = "Null"

Dave
0
 
LVL 65

Accepted Solution

by:
rockiroads earned 500 total points
ID: 17133291
DLOOKUP always returns null if no record foind

Flavo has given u the right syntax. The other way  is    If IsNull(varx) = True then



Alternativly, u can use NZ to return a string instead

varX = NZ(DLookup("[First]", "Identipass", "[Number]= " & CardNumber),"")
if varX = "" then
    msgbox "Not found"


0
 

Author Comment

by:paries
ID: 17133436
If varX Is Null then    gave me a runtime error 424 for some reason.  The other suggestion worked great.  Thanks
0
U.S. Department of Agriculture and Acronis Access

With the new era of mobile computing, smartphones and tablets, wireless communications and cloud services, the USDA sought to take advantage of a mobilized workforce and the blurring lines between personal and corporate computing resources.

 
LVL 34

Expert Comment

by:flavo
ID: 17133475
what?
0
 
LVL 34

Expert Comment

by:flavo
ID: 17133500
Well I'll be...I doesn't work :-(

Dave
0
 
LVL 65

Expert Comment

by:rockiroads
ID: 17133615
Dave, thinking about it, I think may be it will work for object references only
0
 
LVL 34

Expert Comment

by:flavo
ID: 17134297
Yeap :-(
0

Featured Post

Enroll in June's Course of the Month

June's Course of the Month is now available! Every 10 seconds, a consumer gets hit with ransomware. Refresh your knowledge of ransomware best practices by enrolling in this month's complimentary course for Premium Members, Team Accounts, and Qualified Experts.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In earlier versions of Windows (XP and before), you could drag a database to the taskbar, where it would appear as a taskbar icon to open that database.  This article shows how to recreate this functionality in Windows 7 through 10.
Traditionally, the method to display pictures in Access forms and reports is to first download them from URLs to a folder, record the path in a table and then let the form or report pull the pictures from that folder. But why not let Windows retr…
Using Microsoft Access, learn some simple rules for how to construct tables in a relational database. Split up all multi-value fields into single values: Split up fields that belong to other things into separate tables: Make sure that all record…
Do you want to know how to make a graph with Microsoft Access? First, create a query with the data for the chart. Then make a blank form and add a chart control. This video also shows how to change what data is displayed on the graph as well as form…

726 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question