title: No value given for one or more required parameters c#
body: <p>An error appear when i want to execute my SQL statement in C# application, which it's:</p>
  
  <blockquote>
    <p>No value given for one or more required parameters.</p>
  </blockquote>
  
  <p>I'm using c# with MS access database.
  This is my code:</p>
  
  <pre><code>string string2 = "";
  
  if (radButton2 != null)
  {
       string2 = " and signaal1.info='" + radButton2.Text + "' ";
  }
  else
       string2 = " and signaal1.info='0' ";
  if (radButton3 != null)
  {
       string2 += " and situation.info='" + radButton3.Text + "' ";
  }
  OleDbCommand cmd = new OleDbCommand("SELECT actionz.info, relationz.id AS actionz FROM ((((relationz LEFT OUTER JOIN conditions ON relationz.conditions_id = conditions.id) LEFT OUTER JOIN situation ON relationz.situation_id = situation.id) LEFT OUTER JOIN car_type ON relationz.car_id = car_type.id) LEFT OUTER JOIN actionz ON relationz.action_id = actionz.id) LEFT OUTER JOIN signal AS signaal1 ON relationz.signal_id = signaal1.id where car_type.info='" + radButton1.Text + "' " + string2 + "  ORDER BY conditions.id ASC", objConn);
  //cmd.Parameters.AddWithValue("@car_type", radButton1.Text);
  
  OleDbDataReader dataReader = cmd.ExecuteReader();
  </code></pre>