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
Solved

Problem with DLookup/null records in Access Project

Posted on 2003-12-02
3
375 Views
Last Modified: 2012-08-13
I'm working on an Access Project using SQL Server 7 database.
I'm having a problem with the DLookup function.

Here is an example of my problem:

sExpr = "CASE WHEN [FirstName]=NULL THEN 'No First Name' ELSE [FirstName] END"
sResult = DLookup(sExpr, "Network", "NetworkID=18436")

If FirstName record is null, it returns:
  Error:
  Run-time error '94':
  Invalid use of Null

If FirstName record is not null:
  sResult = 'Rob'
-----------------
If I change the expression syntax to:
sExpr = "CASE WHEN [FirstName]<>NULL THEN [FirstName] ELSE 'No First Name' END"
sResult = DLookup(sExpr, "Network", "NetworkID=18436")

If FirstName record is null:
sResult = 'No First Name'

If FirstName record is not null:
sResult = NULL
** I need this to return the value of [FirstName] if it is not null! **

Can somebody tell me how to write this expression so that DLookup can use it and be able to handle null records?
Thanks!

~Rob
0
Comment
Question by:rfiddler
3 Comments
 
LVL 8

Accepted Solution

by:
Benjamin_Luk earned 50 total points
ID: 9863623
change :
sResult = DLookup(sExpr, "Network", "NetworkID=18436")
To:
sResult = NZ(DLookup(sExpr, "Network", "NetworkID=18436"),"")

Regards

Ben
0
 
LVL 5

Assisted Solution

by:morpheus30
morpheus30 earned 30 total points
ID: 9863767
BTW, the line:
sExpr = "CASE WHEN [FirstName]=NULL THEN 'No First Name' ELSE [FirstName] END"

should be:

sExpr = "CASE WHEN [FirstName] IS NULL THEN 'No First Name' ELSE [FirstName] END"

Then you can use DLookup as suggested by Benjamin_Luk.

My two cents...
0
 

Author Comment

by:rfiddler
ID: 9870756
Thanks Ben and Morpheus!
It's working now.

I'm increasing the points and rewarding Morpheus for the two cents as well.

Thanks again.

~Rob
0

Featured Post

Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

Question has a verified solution.

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

In a multiple monitor setup, if you don't want to use AutoCenter to position your popup forms, you have a problem: where will they appear?  Sometimes you may have an additional problem: where the devil did they go?  If you last had a popup form open…
A simple tool to export all objects of two Access files as text and compare it with Meld, a free diff tool.
Get people started with the utilization of class modules. Class modules can be a powerful tool in Microsoft Access. They allow you to create self-contained objects that encapsulate functionality. They can easily hide the complexity of a process from…
In Microsoft Access, learn how to use Dlookup and other domain aggregate functions and one method of specifying a string value within a string. Specify the first argument, which is the expression to be returned: Specify the second argument, which …

790 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