title: Type Conversion Error: System.Linq.IQueryable(string)' to System.Linq.ParallelQuery(int)'
body: <p>I have two tables in my database Element and Entity, given an el_id(element id) i would like to extract the ent_id(entity id) from the Element table and ent_type_id(Entity type) from Entity table, i have an ent_id column common in both the tables but it is int in Element table and String in the Entity table, following is the code, help me resolve it.</p>
  
  <pre><code>  var ent_ids = _context.Elements.Where(e =&gt; el_ids.Contains(e.el_id)).Select(el =&gt; el.ent_id);
    var ent_type_ids = _context.Entities.Where(e =&gt; ent_ids.Contains(e.ent_id)).Select(el =&gt; el.ent_type_id);
  </code></pre>
  
  <p>Error: </p>
  
  <pre><code>Instance argument: cannot convert from 'System.Linq.IQueryable(string)' to 'System.Linq.ParallelQuery(int)'
  </code></pre>
  
  <p>This comes for the second line of the code.</p>
  
  <p>Edit: added models from comment below.</p>
  
  <p>Entities Model: </p>
  
  <pre><code>public partial class Entity 
  { 
      public int ent_id { get; set; } 
      public Nullable&lt;int&gt; document_id { get; set; } 
  } 
  </code></pre>
  
  <p>Elements Model:</p>
  
  <pre><code>public partial class Element 
  { 
      public int el_id { get; set; } 
      public string ent_id { get; set; } 
  }
  </code></pre>