title: LINQ how to handle null values
body: <p>sorry for bad english;</p>
  
  <p>my code;</p>
  
  <pre><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()
  </code></pre>
  
  <p>Some rows contain a null value;
  How do I handle null lines?</p>
  
  <p>Output:</p>
  
  <pre><code>Marmara 40
  Ege     10
  Akdeniz 2
  ...
  </code></pre>