I am Kind of new to coredata and I want to fetch the attributes related to a record. I use the following code to insert a record.
let entityDescription = NSEntityDescription.entity(forEntityName: "Person", in: mainContext!)
let newPerson = NSManagedObject(entity: entityDescription!,insertInto: mainContext)
let entityAddress = NSEntityDescription.entity(forEntityName: "Address", in: mainContext!)
let newAddress = NSManagedObject(entity: entityAddress!,insertInto: mainContext)
let otherAddress = NSManagedObject(entity: entityAddress!, insertInto: mainContext)
newPerson.setValue("Bart", forKey: "first")
newPerson.setValue("Jacobs", forKey: "last")
newPerson.setValue(44, forKey: "age")
newAddress.setValue("Main Street", forKey: "street")
newAddress.setValue("Boston", forKey: "city")
newPerson.setValue(NSSet(object: newAddress), forKey: "addresses")
otherAddress.setValue("5th Avenue", forKey:"street")
otherAddress.setValue("New York", forKey:"city")
// Add Address to Person
let addresses = newPerson.mutableSetValue(forKey: "addresses")
addresses.add(otherAddress)
// Set First and Last Name
do {
try newPerson.managedObjectContext?.save()
}
catch
{
print("Couldnot do this op \(error)")
}
My CoreData relations are as the following
and I fetch the user with the following code
let fetchRequest = NSFetchRequest<NSFetchRequestResult>()
let entityDescription = NSEntityDescription.entity(forEntityName: "Person", in: mainContext!)
fetchRequest.entity = entityDescription
fetchRequest.predicate = NSPredicate(value: true)
do{
let result = try self.mainContext?.fetch(fetchRequest)
for personTest in result!
{
print(personTest)
}
if ((result?.count)! > 0)
{
let person = result![0] as! NSManagedObject
print(person.value(forKey: "first"))
}
}
catch
{
let fetchError = error as NSError
print(fetchError)
}
my question how can I fetch the addresses related to the current person
You don't fetch them, you access them via the addresses
attribute
let adresses = personTest.adresses