title: how to check for NULL returned from stored procedure?
body: <p>I need to check if my stored procedure returned null value.
  Currently I have the following code:</p>
  
  <pre><code>public static bool MyMethod(String isoNum)
  {
      SqlConnection conn = null;
      bool regionExists = true;
      try
      {
          using (conn = new SqlConnection(ConfigurationManager.ConnectionStrings["String"].ConnectionString))
          {
              using (SqlCommand cmd = new SqlCommand("SPU_GetRegionBasedOnIso", conn))
              {
                  cmd.CommandType = CommandType.StoredProcedure;
                  cmd.Parameters.AddWithValue("@isoNum", isoNum);
                  using (SqlDataReader dr = cmd.ExecuteReader())
                  {
                  **&lt;&lt;Here I need to check for NULL value&gt;&gt;** 
                  }
  
              }
          }
      }
      catch (Exception e)
      {
          throw new System.Exception(e.Message.ToString());
      }
      return regionExists;
  }
  </code></pre>
  
  <p>What is the best way to check for NULL here?</p>
  
  <p>Thank you</p>