?
Solved

Check for null string in row

Posted on 2011-09-12
2
Medium Priority
?
271 Views
Last Modified: 2012-05-12
Hi
I'm looping through the columns in a row, and I need to find out if a column contains a null value. So I have code as follows:

For iStage = 1 To MAX_STAGES               
               If Not String.IsNullOrEmpty(rowRenewal("User_" & iStage)) Then

Open in new window


Unfortunately, a null value will actually produce this message:
"Conversion from type 'DBNull' to type 'String' is not valid."

Is there a different way I could check for the null value in this case?
Thanks
0
Comment
Question by:jdhackett
[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
2 Comments
 
LVL 19

Expert Comment

by:Bardobrave
ID: 36522530
Try this:

For iStage = 1 To MAX_STAGES              
               If Not String.IsNullOrEmpty(rowRenewal("User_" & iStage).ToString()) Then

If it don't work try to detect the null value before assigning it to the string

For iStage = 1 To MAX_STAGES              
               If Not rowRenewal("User_" & iStage) = null then
0
 
LVL 18

Accepted Solution

by:
Cluskitt earned 2000 total points
ID: 36522553
Use IsDBNull()

If Not IsDBNull(rowRenewal("User_" & iStage)) Then
0

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

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

Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
If you need to start windows update installation remotely or as a scheduled task you will find this very helpful.
NetCrunch network monitor is a highly extensive platform for network monitoring and alert generation. In this video you'll see a live demo of NetCrunch with most notable features explained in a walk-through manner. You'll also get to know the philos…
Visualize your data even better in Access queries. Given a date and a value, this lesson shows how to compare that value with the previous value, calculate the difference, and display a circle if the value is the same, an up triangle if it increased…

762 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