iOS: Delete ALL Core Data Swift

Question

I am a little confused as to how to delete all core data in swift. I have created a button with an IBAction linked. On the click of the button I have the following:

let appDel: foodforteethAppDelegate = UIApplication.sharedApplication().delegate as foodforteethAppDelegate     let context: NSManagedObjectContext = appDel.managedObjectContext 

Then I've messed around with various methods to try and delete all the core data content but I can't seem to get it to work. I've used removeAll to delete from a stored array but still can't delete from the core data. I assume I need some type of for loop but unsure how to go about making it from the request.

I have tried applying the basic principle of deleting a single row

func tableView(tableView: UITableView!, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath!) {      let appDel: foodforteethAppDelegate = UIApplication.sharedApplication().delegate as foodforteethAppDelegate     let context:NSManagedObjectContext = appDel.managedObjectContext      if editingStyle == UITableViewCellEditingStyle.Delete {          if let tv = tblTasks {             context.deleteObject(myList[indexPath!.row] as NSManagedObject)             myList.removeAtIndex(indexPath!.row)             tv.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: UITableViewRowAnimation.Fade)         }          var error: NSError? = nil         if !context.save(&error) {             abort()         }      }  } 

However, the issue with this is that when I click a button, I don't have the indexPath value and also I need to loop through all the values which I can't seem to do with context.

Answer 1

Try this simple solution:

func deleteAllData(entity: String) {     let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate     let managedContext = appDelegate.managedObjectContext     let fetchRequest = NSFetchRequest(entityName: entity)     fetchRequest.returnsObjectsAsFaults = false      do      {         let results = try managedContext.executeFetchRequest(fetchRequest)         for managedObject in results         {             let managedObjectData:NSManagedObject = managedObject as! NSManagedObject             managedContext.deleteObject(managedObjectData)         }     } catch let error as NSError {         print("Detele all data in \(entity) error : \(error) \(error.userInfo)")     } } 

Swift 4

func deleteAllData(_ entity:String) {     let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: entity)     fetchRequest.returnsObjectsAsFaults = false     do {         let results = try dataController.viewContext.fetch(fetchRequest)         for object in results {             guard let objectData = object as? NSManagedObject else {continue}             dataController.viewContext.delete(objectData)         }     } catch let error {         print("Detele all data in \(entity) error :", error)     } } 

Implementation:

 self.deleteAllData("your_entityName") 

Answer 2

You can use destroyPersistentStore starting in iOS 9.0 and Swift 3:

public func clearDatabase() {     guard let url = persistentContainer.persistentStoreDescriptions.first?.url else { return }          let persistentStoreCoordinator = persistentContainer.persistentStoreCoordinator       do {          try persistentStoreCoordinator.destroyPersistentStore(at:url, ofType: NSSQLiteStoreType, options: nil)          try persistentStoreCoordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: nil)      } catch {          print("Attempted to clear persistent store: " + error.localizedDescription)      } }