title: Include path expression must refer to a navigation property defined on the type
body: <p>I've two models say <strong>"Page"</strong> and <strong>"Product"</strong> Product's PageID refers to Page's ID</p>
  
  <p>and in my Product Index View, I need to get the Page list as a drop-down, for that I'm using </p>
  
  <pre><code>public ViewResult Index()
  {
     var products = _db.Products.Include(p =&gt; p.Page);
              return View(products.ToList());
  }
  </code></pre>
  
  <p>But what I need is only those pages whose <strong>PageGroup</strong> property has a value <em>'Product'</em>. for that I used</p>
  
  <pre><code>public ViewResult Index()
  {
      var products = _db.Products.Include(p =&gt; p.Page.PageGroup
                                     .Contains(PageGroup.Product.ToString()));
      return View(products.ToList());
  } 
  </code></pre>
  
  <p>It's giving an error as follows:</p>
  
  <blockquote>
    <p>The Include path expression must refer to a navigation property
    defined on the type. Use dotted paths for reference navigation
    properties and the Select operator for collection navigation
    properties. Parameter name: path</p>
  </blockquote>