Question Linq join typed to untyped help with group by and count

[dsk96m]

I am trying to write a linq query and having a fit trying to figure it out. Am not very good with linq, just the basics. I code in vb. So I created a datatable in code, then want to write a query that joins it to a typed datatable. Here is what i have so far:

        Dim dt As New DataTable
        dt.Columns.Add("cctrid", gettype(integer))

       .......Add some rows to dt here.

        Dim query = From a In dt
                    Join b In EMS_DS.TEMSCCTR
                    On a.cctrid Equals b.cctr_id
                     Group By a.cctrid Into cctrcnt = Count(a.cctrid)
                     Select a.cctrid, cctrcnt

         cctrgc.datasource=query
    End Sub

I have tried a.field(of integer)("cctrid") and many other things, but I keep getting a type expected error.

Please help.

 

[JohnH]

I have tried a.field(of integer)("cctrid")

That would be correct, but Linq needs a 'name', so assign it to a variable, and use that later in query:

Let a_cctrid = a.Field(Of Integer)("cctrid")

 

[dsk96m]

Where do i put that, in the join or group by?

 

[dsk96m]

i messed up in the first place

        Dim query = From a In dt
                    Join b In EMS_DS.TEMSCCTR
                    On a.cctrid Equals b.cctr_id
                     Group By a.cctrid Into cctrcnt = Count(a.cctrid)
                     Select b.cctr_cd, cctrcnt

But where do i use what you said?

 

[dsk96m]

Is it this:

        Dim query = From a In dt
                    Let a_cctrid = a.Field(Of Integer)("cctrid")
                    Join b In EMS_DS.TEMSCCTR
                    On a_cctrid Equals b.cctr_id
                    Group a_cctrid By cctr = b.cctr_cd, cctrcnt = a_cctrid Into Group
                    Select New With
                           {
                               .cctr = cctr,
                               .cctrcnt = Group.Count()
                           }

Still get type expected

 

[JohnH]

I don't see the problem.

 

[dsk96m]

Still coming up type expected

 

[JohnH]

I don't see the problem.

Here I kind of replicated the code and didn't get any error from compiler. I also didn't see any other problems visually with what you posted. I still don't see the problem or where it could be.