CODEWITHSUNDEEP
c#linqlinq-to-sql
Jerry
Jerry

Reputation: 4557

C# Why is Linq crashing about a Null if the value is not null?

I have a simple three table reference. It looks plain enough. The associations there are created in the DBML. They are not actually foreign keys in the table definition. Why? That's a long story. Trust me when I say, I've fought that battle and lost.

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When I attempt to add a new FileType record using LINQ, it crashes with the error: Cannot insert the value NULL into column Id, table FileType.

            _fileType = new FileType()
            {
                Id = def.ID, // This is the integer "1"
                Name = def.Name,
                FileCategoryId = def.Category.ID,
                DateLabel = def.DateLabel,
                FileNamePrefix = def.Prefix,
                FolderName = def.Folder,
                CreateInspection = 0
            };

            try
            {
                dc.FileTypes.InsertOnSubmit(_fileType);
                dc.SubmitChanges();
            }
            catch (Exception ex) 
            {
                MessageBox.Show(ex.Message); 
            }

But if you'll notice the code, Id is being set. I've checked the value and it is not null. It is an integer. What am I missing or doing wrong??

I did check to make sure that the FileCategory record of the correct ID exists. Is there anything else I'm missing?

Upvotes: 4

Views: 426

Answers (2)

Jerry
Jerry

Reputation: 4557

In your table mapping, is the field marked as 'Auto Generated Value' in the Properties pane? I've had insert/update issues with that before... – Tieson T. Mar 7 at 6:52

I would give him the props for this, but he left this as a comment, and not an official answer.

Upvotes: 0

leppie
leppie

Reputation: 117310

I have seen something like this before.

It happens when you only assign the 'id' and not the related object.

Try the following:

new FileType
{
  FileCategory = def.Category,
  ...
}

Upvotes: 2

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