Left outer join null using VB.NET and LINQ

Posted by jvcoach23 on Stack Overflow See other posts from Stack Overflow or by jvcoach23
Published on 2010-09-27T15:30:16Z Indexed on 2014/08/25 10:20 UTC
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I've got what I think is a working left outer join LINQ query, but I'm having problems with the select because of null values in the right hand side of the join. Here is what I have so far

 Dim Os = From e In oExcel
        Group Join c In oClassIndexS On c.tClassCode Equals Mid(e.ClassCode, 1, 4)
        Into right1 = Group _
        From c In right1.DefaultIfEmpty

I want to return all of e and one column from c called tClassCode. I was wondering what the syntax would be. As you can see, I'm using VB.NET.

Update...

Here is the query doing join where I get the error:

_message = "Object reference not set to an instance of an object."

 Dim Os = From e In oExcel
             Group Join c In oClassIndexS On c.tClassCode Equals Mid(e.ClassCode, 1, 4)
             Into right1 = Group _
             From c In right1.DefaultIfEmpty
        Select e, c.tClassCode

If I remove the c.tClassCode from the select, the query runs without error. So I thought perhaps I needed to do a select new, but I don't think I was doing that correctly either.

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