LINQ to SQL - Nullable INT in ForeignKey = "Cannot create an association..."

Question

I have a table that has a primary key that's an INT... I have another table, that has a foreignkey relationship to that first table, but it's a NULLABLE INT.

This is perfectly ok, and 100% acceptable to SQL... however LINQ to SQL is complaining about mismatched types ("int to Nullable[int]").

Error Message: Cannot create an association "Store_People". Properties do not have matching types: "PersonID", "ID".

How do I solve this so that the designer stops yelling at a 100% correct usage of SQL?

Answer 1

I found the problem. You can create the association ONLY if the parent class doesn't have the Nullable field as the key.

So, this:

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will cause this error:

alt text http://www.singingeels.com/Articles/UserImage.aspx?ImageID=19ed54aa-9f4f-4d5c-ba18-4996509d2da7

...but this:

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will work perfectly.

That looks like a bug (or at least, a stupidity of LINQ to SQL)... but I love it other than that.