title: system.linq.IQueryable does not contain a definition for 'To'
body: <p>I get an error in this code:</p>
  
  <p>this is the code:</p>
  
  <pre><code>  public IHttpActionResult  Get()
      {
          var books = unit.Books.All;
  
          var response = books.To&lt;BookDto&gt;();
  
          return Ok(response);
      }
  </code></pre>
  
  <p>and right on books.To()  I am getting this error:</p>
  
  <blockquote>
    <p>system.linq.IQueryable does not contain a definition for 'To' and<br>
    extension method 'to' accepting a first argument of type 
    'system.linq.IQueryable' could be found. you you missing a using 
    directive or an assembly reference?</p>
  </blockquote>
  
  <p>I looked at this but no help.</p>
  
  <p><a href="https://stackoverflow.com/questions/20017579/iqueryablet-does-not-contain-a-definition-for-include-and-no-extension-metho">IQueryable&lt;T&gt; does not contain a definition for &#39;Include&#39; and no extension method &#39;Include&#39;</a></p>
  
  <p>I have using System.Data.Entity; and also I have installed the EF from NuGet , but as the solution in the link I cant get the "QueryableExtensions" available in </p>
  
  <pre><code> using System.Data.Entity.QueryableExtensions
  </code></pre>