Group By with substring throws an error

[Frank Schürer]

Hi,

i have this code snippet here and i try to get it working...

Dim  Result = (From s In scope.Extent(Of ZipCodes)() _
          Where s.Coord = sValue _
          Group s By s.ZipCode.Substring(0, 2), s.Coord Into g = Group _
          Select  New  With  {.Region = ZipCode.Substring(0, 2), Coord})

The interpreter says the following:
Range variable name can be inferred only from a simple or qualified name with no arguments
Has anybody came across this issue?

[Jordan]

Hello Frank Schürer,

It seems that you usually get such an error when you have not given a name to some expression.
If you write the query like in the bellow snipped the error disappears:

Dim Result = From s In zipCodes _
            Where s.Coord = "coord" _
            Group s By start = s.Name.Substring(0, 2), s.Coord Into Group _
            Select New With {.Region = start}

Notice that the Substring expression is assigned to the start variable.
You can take a look at the following blog post for more information:
http://thedatafarm.com/blog/data-access/a-few-things-you-can-t-do-with-ef-queries-which-you-won-t-find-out-until-runtime/

Sincerely yours,
Jordan
the Telerik team