title: Core Data Fetch Request Error
body: <p>I am trying to fetch record based on attribute name.</p>
  
  <p>I also try to search similar issue but I am not able to find solution so I am posting question ...</p>
  
  <p>but I got exception while fetching:</p>
  
  <pre><code>[error] error: exception handling request: &lt;NSSQLFetchRequestContext: 0x1c019a270&gt; , keypath audio_1.m4a not found in entity &lt;NSSQLEntity answer id=8&gt; with userInfo of (null)
  CoreData: error: exception handling request: &lt;NSSQLFetchRequestContext: 0x1c019a270&gt; , keypath audio_1.m4a not found in entity &lt;NSSQLEntity answer id=8&gt; with userInfo of (null)
  2017-09-28 19:03:36.725060+0530 app[9684:891158] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'keypath audio_1.m4a not found in entity &lt;NSSQLEntity answer id=8&gt;'
  </code></pre>
  
  <p>My code :</p>
  
  <pre><code>let fetchRequest = NSFetchRequest&lt;NSFetchRequestResult&gt;(entityName: Entity)
  
      if let predic = predicate_str{
          let predicate = NSPredicate(format: predic)
          fetchRequest.predicate=predicate
      }
  
      do {
          let arr = try appsession.managedObjectContext.fetch(fetchRequest) //CRASHED
  
  
          // success ...
      } catch let error as NSError {
          // failure
          print("Fetch failed: \(error.localizedDescription)")
          return(nil,error)
      }
  </code></pre>
  
  <p><strong>Thank you,</strong></p>