title: Check if value exist in DBF database
body: <p>I am trying to check if value "IAV-1419" exist in second column (<code>ColName</code>) in database named <code>PROMGL.DBF</code>.</p>
  
  <p>I get this error : No value give for one or more required parameters</p>
  
  <pre><code>        Dim con As New OleDbConnection
      Dim cmd As New OleDbCommand
  
      Dim FilePath As String = "C:\"
      Dim DBF_File As String = "PROMGL"
      Dim ColName As String = "[NALOG,C,8]"
      con.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" &amp; FilePath &amp; _
      " ;Extended Properties=dBASE IV"
      cmd = New OleDbCommand("SELECT * FROM PROMGL WHERE [NALOG,C,8] = @NAL")
  
  
      cmd.Connection = con
      con.Open()
      cmd.Parameters.AddWithValue("@NAL", "IAV-1419")
      Using reader As OleDbDataReader = cmd.ExecuteReader()
          If reader.HasRows Then
              con.Close()
              Label6.Text = "EXIST"
              TextBox1.Text = ""
              TextBox1.Focus()
  
          Else
              Label6.Text = "DOESN'T EXIST"
  
          End If
      End Using
  </code></pre>
  
  <p>I am stuck here, if anyone could please check this code for me. </p>