digital_soul
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BC30002: Type 'Column' is not defined. Error when usign Linq to SQL class
Hi Experts
I am getting this error when running a page with a gridview bound to a LinqDataSource that is using a Linq to SQL class as its data context.
The error is pointing to the line below in the designer.vb file
Line 907: <Column(Storage:="_Managem ent_System _ID", DbType:="Int")> _
Line 908: Public Property Management_System_ID() As System.Nullable(Of Integer)
Any ideas?
Thanks
Stewart
I am getting this error when running a page with a gridview bound to a LinqDataSource that is using a Linq to SQL class as its data context.
The error is pointing to the line below in the designer.vb file
Line 907: <Column(Storage:="_Managem
Line 908: Public Property Management_System_ID() As System.Nullable(Of Integer)
Any ideas?
Thanks
Stewart
The ColumnAttribute class is defined in the System.Data.Linq.Mapping namespace, which is in the System.Data.Linq assembly. You need a reference to this assembly in your project.
ASKER
The auto genarated Class file where the error is occuring does include
Imports System.Data.Linq
Imports System.Data.Linq.Mapping
Imports System.Data.Linq
Imports System.Data.Linq.Mapping
That is an Imports statement, but you also need a reference in your project to the System.Data.Linq assembly.
ASKER
In Visual Studio I am selecting Add reference and then selecting System.Data.Linq but its still not working.
Should doing this create a reference in my Web.Config file?
Should doing this create a reference in my Web.Config file?
Are you working with a web application or web site (project file or not)?
ASKER
Yes its a Project file
If you have a project file, then it should be under the References node in the Solution Explorer.
Snapshot.png
Snapshot.png
ASKER
Hi
There is a reference to System.Data.Linq Under Project - Properties - references. See attached screengrab
Cheers
screengrab.png
There is a reference to System.Data.Linq Under Project - Properties - references. See attached screengrab
Cheers
screengrab.png
I would look again, in the file folder where your code is, and see if you have a .vbproj file. It looks like you have a Web Site model (File | New Web Site), instead of a Web Application model (File | New | VB.NET | Web | Web Application). I asked that question before because there are differences between how the two models behave with ASP.NET.
I see that you are referencing System.Data.Linq v. 3.5, but it is not coming from the Global Assembly Cache (GAC). I have ASP.NET 4.0, and you can see the difference between the references in this image:
Snapshot.png
I see that you are referencing System.Data.Linq v. 3.5, but it is not coming from the Global Assembly Cache (GAC). I have ASP.NET 4.0, and you can see the difference between the references in this image:
Snapshot.png
ASKER
Its an ASP.NET Web Application created via File - New project as its part of a multi-project solution. There is a vbproj file.
VB.NET projects are different than C# projects. With C# projects, you will see a References node in the Solution Explorer tree. If you have the correct reference, and the correct Imports System.Data.Linq statements, then you have a system that is getting confused. When ASP.NET compiles a web page, it includes all the referenced DLLs in the \bin folder. I can't think of a specific reason for this, off the top of my head.
ASKER
I appear to have solved it. For some reaosn Visual Studio wasn't adding
<add assembly="System.Data.Linq , Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C56193 4E089"/>
to the Web.config file. Ive assed this reference now and the page compiles fine. Thanks for your help though.
<add assembly="System.Data.Linq
to the Web.config file. Ive assed this reference now and the page compiles fine. Thanks for your help though.
ASKER
Actually the problem is only partially solved. I can now set up a LInqDataSource and bind it to a datagrid and compile this ok. I cant seem to access my DataContext Class programtically though. Is there a difference between how you would access this class in a Project as opposed to a website? usually in a website id just create the Linq to SQL class using the designer and instantly be able to reference it in code ala:
Dim myDataContext As LinqClassDataContext = New LinqClassDataContext ()
In my Project file though Visuaol Studio is not recognising my DataContext Class, despite the file having been automatically generated as usual.
Dim myDataContext As LinqClassDataContext = New LinqClassDataContext ()
In my Project file though Visuaol Studio is not recognising my DataContext Class, despite the file having been automatically generated as usual.
ASKER
It seemed to be because I was placing my DataContext classes in an App_Code folder which is presumbaly not a recognised Project directory as it isnt an option from Add ASP.NET Folder. As soon as I created the class in the root I was able to access it from code.
Is there a reason why the App_Code folder wouldnt work in a project as it does in a website?
Cheers
Is there a reason why the App_Code folder wouldnt work in a project as it does in a website?
Cheers
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