CoreData : Insert,update,delete,fetch data from the database

Posted By : Nitin Bhatt | 12-May-2016

swift

In this example i have Created one Entity “EmployeeDetails”.

To create an entity,click the + button in the bottom-left of the editor view and name the entity “EmployeeDetails”

Once you create a entity, you need to add attributes to it , Click on the +button in the attributes section to do that. I have create the three entities id, name,contactNumber.

Create the subclass of NSManagedObject which is based on the entity defined in the XXX.xcdatamodel file

To create a file click on XXX.xcdatamodeld (Right Click) -> New File -> CoreData(iOS) -> NSManagedObject subclass

Insert Data in EmployeeDetails : -

    class func createInManagedObjectContext(id: String, name: String,contactNumber: String) -> EmployeeDetails {
        
        let managedObjectContext = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
        
        let newItem = NSEntityDescription.insertNewObjectForEntityForName("EmployeeDetails", inManagedObjectContext: managedObjectContext) as! EmployeeDetails
        
        newItem.id = id
        newItem.name = name
        newItem.contactNumber = contactNumber

        
        var error: NSError?
        do {
            try managedObjectContext.save()
        } catch let error1 as NSError {
            error = error1
            print("Could not save \(error), \(error?.userInfo)")
        }
        
        return newItem
    }

Fetch Data from EmployeeDetails : -

    class func fetchEmployeeDetails() -> [AnyObject] {
        var dataToReturn = [AnyObject]()
        var data = Dictionary < String , AnyObject >()
        let appDelegate =
            UIApplication.sharedApplication().delegate as! AppDelegate
        let managedContext = appDelegate.managedObjectContext
        let fetchRequest = NSFetchRequest(entityName:"EmployeeDetails")
        var error: NSError?
        
        do{
            let fetchedResults =
                try managedContext.executeFetchRequest(fetchRequest) as? [NSManagedObject]
            
            if let results = fetchedResults {
                for index in 0 ..< results.count {
                    let match = results[index] as NSManagedObject
                    data = ["id" : match.valueForKey("id") as! String,
                            "name" : match.valueForKey("name") as! String,
                            "contactNumber" : match.valueForKey("contactNumber") as! String,
                    ]
                    dataToReturn.append(data)
                }
            } else {
                print("Could not fetch \(error), \(error!.userInfo)")
            }
        } catch let error1 as NSError {
            error = error1
            print("Could not fetch \(error),\(error!.userInfo)")
        }
        return dataToReturn
    }

Update contactNumber in Employee Details :-

    class func updateContactNumber(id:String,contactNumber:String){
        let appDel: AppDelegate = (UIApplication.sharedApplication().delegate as! AppDelegate)
        let context: NSManagedObjectContext = appDel.managedObjectContext
        
        let request = NSFetchRequest(entityName: "EmployeeDetails")
        request.predicate = NSPredicate(format: "id = %@", id)
        
        if let fetchResults = (try? appDel.managedObjectContext.executeFetchRequest(request)) as? [NSManagedObject] {
            if fetchResults.count != 0{
                var managedObject = fetchResults as! [EmployeeDetails]
                
                managedObject[0].setValue(contactNumber, forKey: "contactNumber")
                
                do {
                    try context.save()
                } catch _ {
                }
            }
        }
    }

Delete Data from Employee Details : -

     class func deleteEmployeeDetails() {
        let appDelegate =
            UIApplication.sharedApplication().delegate as! AppDelegate
        let fetchRequest = NSFetchRequest(entityName: "EmployeeDetails")
        if let fetchResults = (try? appDelegate.managedObjectContext.executeFetchRequest(fetchRequest)) as? [EmployeeDetails] {
            var preferncesData = fetchResults
            if preferncesData.count > 0{
                let appDel:AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
                let context:NSManagedObjectContext = appDel.managedObjectContext
                for index in 0...preferncesData.count - 1{
                    context.deleteObject(preferncesData[index] as NSManagedObject)
                }
                preferncesData.removeAll(keepCapacity: false)
                do {
                    try context.save()
                } catch _ {
                }
            }
        }
    }

THANKS