>>>>From the above link:
>>>>Although this is useful, it does not allow tables to be created from a sequence of scalar types, from queries that project anonymous types, or from queries that perform table joins
>>>
>>>Right.
>>>
>>>I tried implementing the MS documented solution of creating custom CopyToTable method, but this seems to lead to other problems. First warning message I posted. I found I need to set ComVisible(false) to fix that message.
>>>
>>>But now I am getting the other warning
>>>
>>>Warning 4 "C:\Dev\Siriusware.Middleware\Siriusware.Middleware\bin\Debug\Siriusware.Middleware.dll" does not contain any types that can be registered for COM Interop. Siriusware.Middleware
>>>
>>>So, I am not sure if I need to pursue that method or try to figure something else. My end result is to produce a string and the only reason I need a datatable is because the method that generates that string accepts datatable.
>>
>>Since your original query uses a join (and CopyToDataTable() doesn't support it) there doesn't seem much point in pursuing that approach :-}
>>
>>Seems to me your options are:
>>(a) Convert the query results into the required DataTable using code or
>>(b) Writing a version of the method that accepts the IEnumerable.
>>
>>If the code in the method is complex then maybe write an overload that accepts the IEnumerable, converts it to a DataTable and passes that to the existing method?
>
>The code in the method is not very complex, but it has several implementations depending on Return Type.
>
>I am going to try now this solution http://archive.msdn.microsoft.com/LinqEntityDataReader by MS employee David Browne.

Like this:

    DataTable dt = new DataTable();
            dt.Load(resultingQuery.AsDataReader());

Interested to know if it works.....