LINQ how to handle null values - vb.net

Question

sorry for bad english;
my code;
Dim otherDT As DataTable = retDS1.Tables(0)
Dim dt As New DataTable
dt.Columns.Add("COGRAFI_BOLGE_ADI")
dt.Columns.Add("Count")
Dim query = (From dr In (From d In otherDT.AsEnumerable Select New With {.COGRAFI_BOLGE_ADI = d("COGRAFI_BOLGE_ADI")}) Select dr.COGRAFI_BOLGE_ADI Distinct)
For Each colName As String In query
Dim cName = colName
Dim cCount = (From row In otherDT.Rows Select row Where row("COGRAFI_BOLGE_ADI").ToString = cName).Count
dt.Rows.Add(colName, cCount)
Next
GridView1.DataSource = dt
GridView1.DataBind()
Some rows contain a null value;
How do I handle null lines?
Output:
Marmara 40
Ege 10
Akdeniz 2
...

Answer 1

Not really clear what you are asking, but are you looking for something like this:
Dim otherDT As DataTable = retDS1.Tables(0)
Dim dt As New DataTable
dt.Columns.Add("COGRAFI_BOLGE_ADI")
dt.Columns.Add("Count")
Dim query = (From dr In (From d In otherDT.AsEnumerable
Select New With {.COGRAFI_BOLGE_ADI = d("COGRAFI_BOLGE_ADI")})
Select dr.COGRAFI_BOLGE_ADI Distinct)
For Each colName As String In query
Dim cName As String = colName
Dim cCount As Integer = (From row In otherDT.Rows
Select row
Where row IsNot Nothing AndAlso
row("COGRAFI_BOLGE_ADI") IsNot Nothing AndAlso
row("COGRAFI_BOLGE_ADI").ToString = cName).Count
If cCount > 0 Then
dt.Rows.Add(colName, cCount)
End If
Next
GridView1.DataSource = dt
GridView1.DataBind()