Core Data is a framework which you can use to manage Data or Model
To work with following code, you need to create single view application.
Please select the core data check box when you create the project
Then you have the coredataex.xcdatamodeld to create the Entity and its attribute
Here I have created the User Entity and two attributes named firstname and lastname
How to Insert Data
You can write the following code inside the viewDidLoad() method
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let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext let user = User(context: context) user.firstname = "Mark" user.lastname = "Taylor" (UIApplication.shared.delegate as! AppDelegate).saveContext() |
When you run the application it will insert the data into the database.
How to Retrieve Data
If you want to get data from the User entity you can use the following code
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let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext do{ let rows = try context.fetch(User.fetchRequest()) as! [User] for row in rows{ print(row.firstname!) } }catch{} |
How to delete entry
If you want to delete a row you have to select that row first. I am using NSPredicate class to select the recods where firstname is equal to “Mark”
Once you select the row using context.fetch() you can use context.delete() to delete the record from the entity
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let userfecth: NSFetchRequest = User.fetchRequest() userfecth.predicate = NSPredicate(format: "firstname == %@", "Mark") do{ let rows = try context.fetch(userfecth) for row in rows{ context.delete(row) } }catch{} (UIApplication.shared.delegate as! AppDelegate).saveContext() |