how to delete a particular row data in coredata database in swift

Question

PLease help me out

Here is my code

//

import UIKit
import CoreData


class SavedPageViewController: UIViewController, UITableViewDataSource, UITableViewDelegate , NSFetchedResultsControllerDelegate  {


    @IBOutlet weak var tableView: UITableView!

    var tableTitleArray = [String]()
    var tableDetailArray = [String]()
    var tableTypeArray = [String]()
    var tableHoursArray = [String]()
    var tableImageArray = [NSData]()


    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    override func viewWillAppear(animated: Bool) {
// core data - show
         let appDel:AppDelegate = (UIApplication.sharedApplication().delegate as! AppDelegate)
         let context:NSManagedObjectContext = appDel.managedObjectContext

        var request = NSFetchRequest(entityName: "SavedIdea")
        request.returnsObjectsAsFaults = false;

        do {
            var result:NSArray = try context.executeFetchRequest(request)

            if (result.count > 0) {
                 self.tableTitleArray = result.valueForKey("heading") as! [String]
                 self.tableDetailArray = result.valueForKey("detail") as! [String]
                 self.tableTypeArray = result.valueForKey("type") as! [String]
                 self.tableHoursArray = result.valueForKey("time") as! [String]
                self.tableImageArray = result.valueForKey("image") as! [NSData]
            }else{
                print("0 result appear....error")}
            tableView.reloadData()
        }catch {
            let fetchError = ("returned error is \(error as! NSError)")
            print(fetchError)
        }
    }


    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        return self.tableTitleArray.count
    }


    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("Cell")! as! OTPTableViewCell

        cell.LabelTitle.text = tableTitleArray[indexPath.row]
        cell.LabelDetail.text = tableDetailArray[indexPath.row]
        cell.LabelType.text = tableTypeArray[indexPath.row]
        cell.LabelHours.text = String(tableHoursArray[indexPath.row])+"h"
        if tableImageArray[indexPath.row].length > 0  {          
            cell.ImgView.image =  UIImage(data: tableImageArray[indexPath.row])
        }else{
            cell.imageWidthConstraints.constant = 0
        }

        return cell
    }


    func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {

    if editingStyle == .Delete {

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


   /*     let deleterequest = NSFetchRequest(entityName: "SavedIdea")
        deleterequest.returnsObjectsAsFaults = false

        do {
            let savedData = try context.executeFetchRequest(deleterequest)

            if savedData.count > 0 {

                for result: AnyObject in savedData{
                    context.deleteObject(result.valueForKey("heading"))
                    print("NSManagedObject has been Deleted")
                }
                try context.save() } } catch {}



     }
    }

i want to delete a complete row from tableview i.e heading,detail,type etc . My entity name is SavedData. I tried few tutorial but they didnt satisfy my needs . when we slide right then delete appear but dont working as i dont know the code.

you are deleting entity itself instead of particular row, Fetch that particular row and perform delete action and reload tableview — Jan49
– Jan49, Commented Aug 29, 2016 at 11:30
With your weird code it is very complicated (and inefficient) to do that. First you have to search and fetch the NSManagedObject because you threw away the reference, then you have to remove the item at row index in all arrays representing the data source, then you have to delete the NSManagedObject in Core Data and finally call deleteRowsAtIndexPaths in the tableView. — vadian
– vadian, Commented Aug 30, 2016 at 7:46

Shobhakar Tiwari · Accepted Answer · 2016-08-30 07:23:06Z

1

This way you can delete Data from coredata based on Entity : Here is simple function to delte user entity data from coredata : Hope it helps //Delete info from Core data

func deleteUserInfo()  {    
    let context = appdelegate.managedObjectContext
    let coord   = appdelegate.persistentStoreCoordinator

    let fetchRequest = NSFetchRequest(entityName: "entityname")
    //Here is the field on which u need to chk which record u want to delete just pass here in value ( acutal value) unique key = field in coredata 
    let predicate = NSPredicate(format: "uniqueKey == %@", "value")
    fetchRequest.predicate = predicate
    if #available(iOS 9.0, *) {
       //You can put condition to delete data accordingly
        let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)

        do {
            try coord.executeRequest(deleteRequest, withContext: context)
        }

        catch let error as NSError {
            //Error handling
        }

        catch {}

    } else {

        // Fallback on earlier versions
        do {

           let users: NSArray = try appdelegate.managedObjectContext.executeFetchRequest(fetchRequest)

        //You can put condition to delete data accordingly
        for user in users {
            appdelegate.managedObjectContext.delete(user)
        }

        try appdelegate.managedObjectContext.save()

        } catch let error as NSError {
            //Error handling
        }

        catch {}
    }
}

edited Aug 30, 2016 at 7:23

answered Aug 29, 2016 at 11:33

Shobhakar Tiwari

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4 Comments

Hitesh Mor Over a year ago

i want to delete the selected Row from table view so i put this code in - func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) { }.......................it is showing me error on this line when i put indexpath.row on user like this ..appDel.managedObjectContext.delete(user(indexPath.row))

Shobhakar Tiwari Over a year ago

chck parameter u passing integer ?

Hitesh Mor Over a year ago

i am Showing my data in viewcontroller using this code -

Shobhakar Tiwari Over a year ago

chck updated answer , changed code accordingly , in coredata u need to use Predicate to fetch result and then u can delete just pass value and field according to your requirement

Bhuvaneswari Lakshminarayanan · Accepted Answer · 2019-02-07 08:52:23Z

I hope this will be useful for deleting the particular row using the index position in core data

func tableView(_ tableView: UITableView, commit editingStyle: 

UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) 

{
    let appDelegate = UIApplication.shared.delegate as! AppDelegate

    let context = appDelegate.persistentContainer.viewContext

    let requestDel = NSFetchRequest<NSFetchRequestResult>(entityName: "Contacts")
    requestDel.returnsObjectsAsFaults = false

    do {

        let arrUsrObj = try context.fetch(requestDel)

        let objectUpdate = arrUsrObj as! [NSManagedObject]

            context.delete(objectUpdate[indexPath.row]) // Deleting Object

    } catch {
        print("Failed")
    }

    // Saving the Delete operation
    do {
        try context.save()
        print("deleted")
        fetch()


    } catch {
        print("Failed saving")
    }


}

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