Wrox Programmer Forums
Go Back   Wrox Programmer Forums > ASP.NET and ASP > ASP.NET 2.0 > ASP.NET 2.0 Basics
ASP.NET 2.0 Basics If you are new to ASP or ASP.NET programming with version 2.0, this is the forum to begin asking questions. Please also see the Visual Web Developer 2005 forum.
Welcome to the p2p.wrox.com Forums.

You are currently viewing the ASP.NET 2.0 Basics section of the Wrox Programmer to Programmer discussions. This is a community of software programmers and website developers including Wrox book authors and readers. New member registration was closed in 2019. New posts were shut off and the site was archived into this static format as of October 1, 2020. If you require technical support for a Wrox book please contact http://hub.wiley.com
Old October 24th, 2009, 11:31 AM
Registered User
Join Date: Aug 2009
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Default Conversion from type 'DBNull' to type 'Boolean' is not valid.


This is my second time trying to post this to this site so I appologize if its a repeat as the the first one didn't appear to go through.

I'm new to asp.net and am getting the error posted below. I have a formview and it contains fields OT and PT, which are set in the DB as allowing nulls. From what I've found googling this error, I will need codebehind but do not know what to write or what event to post in under.

Any help would be greatly apprecited.

__________________________________________________ ____________

Conversion from type 'DBNull' to type 'Boolean' is not valid.

Source Error:

Line 402: <asp:Label ID="GradeLabel" runat="server" Text='<%# Bind("Grade") %>'></asp:Label><br />
Line 403: OT:
Line 404: <asp:CheckBox ID="OTCheckBox" runat="server" Checked='<%# Bind("OT") %>' Enabled="false" /><br />
Line 405: PT:
Line 406: <asp:CheckBox ID="PTCheckBox" runat="server" Checked='<%# Bind("PT") %>' Enabled="false" /><br />
Old October 24th, 2009, 09:42 PM
Friend of Wrox
Join Date: Nov 2007
Posts: 207
Thanks: 2
Thanked 15 Times in 15 Posts
Default It's due to null...

If you have a field in your db that has no value (null) you code doesn't know what to do with it. Since the check setting requires a boolean (True False) it can't interpret a null. One way around this is to set a default when adding a row to the database. If there is no value chosen OT set it to True and same for PT...

For the rows you already have in the DB you will have to handle them so your code won't bomb out. Assuming you are using MSSQL you can use an isnull statement. Basically it looks like this:

Select Grade, isnull(OT, 'True') as OT, isnull(PT,'True') as PT from myTable
I hope this helps! Also please try not to double post. We will see it the first time you post it. 2 of the same thing just boggs things down.
Jason Hall

Follow me on Twitter @jhall2013

Similar Threads
Thread Thread Starter Forum Replies Last Post
Conversion from type 'DBNull' to type 'Boolean' is not valid. alcsew ASP.NET 2.0 Basics 4 October 28th, 2009 03:38 AM
Conversion from type 'DBNull' to type 'Boolean' is not valid. alcsew ASP.NET 2.0 Basics 0 October 24th, 2009 11:25 AM
Conversion from type 'DBNull' to type 'String' is not valid. phuc2583 ASP.NET 3.5 Professionals 4 October 1st, 2009 09:46 AM
Conversion from type 'DBNull' to type 'String' is GailCG ASP.NET 2.0 Basics 5 February 22nd, 2007 03:12 PM
Conversion from type 'DBNull' to type 'Boolean' is steve35719 VB Databases Basics 4 June 29th, 2006 06:13 PM

Powered by vBulletin®
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright (c) 2020 John Wiley & Sons, Inc.