title: LinQ to Sql project with stored procedures
body: <p>I'm trying to make my first LINQ with asp website so I built a database with one table and I made a stored procedure which selects from this table by the <code>id</code> here it is :   </p>
  
  <pre><code>ALTER PROCEDURE select_article_by_id
  @artcileid int
  AS
      select * from articles where artcileid=@artcileid
      RETURN  
  </code></pre>
  
  <p>then I dragged and droped it into my <code>DataClasses.dbml</code><br>
  when I run the website this problem appear      </p>
  
  <pre><code>An invalid data source is being used for articleDL.
  A valid data source must implement either IListSource or IEnumerable.
  </code></pre>
  
  <p>and gives me this sorce Error :  </p>
  
  <pre><code>Line 16:  string art_id = Request.QueryString["art_id"];
  Line 17:  if (art_id != null)
  Line 18:  articleDL.DataSource = DS.select_article_by_id(int.Parse(art_id)).Single();
  Line 19:  
  Line 20:  else
  </code></pre>