title: SQL Datatable error "Value cannot be null."
body: <p>I am executing a sql query, and I am getting an error <strong>Value cannot be null.
  Parameter name: dataTable</strong>  </p>
  
  <p><strong>Code:</strong>  </p>
  
  <pre><code>                strSQLHost = "select HostBase.AppName from HostBase where HostBase.appid=0" 
                  Dim dtHost As DataTable
                  Dim daHost As SqlDataAdapter = New SqlDataAdapter(strSQLHost, conn)
                  daHost.Fill(dtHost)
  </code></pre>
  
  <p>The error occurs at the <code>daHost.Fill(dtHost)</code><br>
  When I run this query in SQL Enterprise manager, I get a value of 'None'. It's a valid value, not a null value.  </p>
  
  <p>How can I resolve this?</p>