How to check if core data is empty - swift

Question

How do I check if core data is empty using Swift. I tried this method:
var people = [NSManagedObject]()
if people == nil {
}
but this results in this error:
“binary operator '==' cannot be applied to operands of type [NSManagedObject] and nil”

Answer 1

Swift 3 solution:
var isEmpty: Bool {
do {
let request = NSFetchRequest(entityName: YOUR_ENTITY)
let count = try context.count(for: request)
return count == 0
} catch {
return true
}
}

Answer 2

Based on Dejan Skledar's answer I got rid of some compiler warnings and adopted it to Swift 2.0.
func entityIsEmpty(entity: String) -> Bool
{
let context = NSManagedObjectContext()
let request = NSFetchRequest(entityName: entity)
var results : NSArray?
do {
results = try context.executeFetchRequest(request) as! [NSManagedObject]
return results.count == 0
} catch let error as NSError {
// failure
print("Error: \(error.debugDescription)")
return true
}
}
However, I am not sure if the if let res=results clause along with its else clause ist required or not.

Answer 3

To check if the Core Database is empty you have to make a NSFetchRequest on the entity you want to check, and check if the results of the request are empty.
You can check it with this function:
func entityIsEmpty(entity: String) -> Bool
{
var appDel:AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
var context = NSManagedObjectContext()
var request = NSFetchRequest(entityName: entity)
var error = NSErrorPointer()
var results:NSArray? = self.context.executeFetchRequest(request, error: error)
if let res = results
{
if res.count == 0
{
return true
}
else
{
return false
}
}
else
{
println("Error: \(error.debugDescription)")
return true
}
}
Or simplier and shorter solution: (using .countForFetchRequest)
func entityIsEmpty(entity: String) -> Bool
{
var appDel:AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
var context = NSManagedObjectContext()
var request = NSFetchRequest(entityName: entity)
var error = NSErrorPointer()
var results:NSArray? = self.context.executeFetchRequest(request, error: error)
var count = context.countForFetchRequest(request, error: error)
if error != nil
{
println("Error: \(error.debugDescription)")
return true
}
else
{
if count == 0
{
return true
}
else
{
return false
}
}
}

Answer 4

SwiftUI Solution
struct ContentView: View {
#Environment(\.managedObjectContext) private var viewContext
#FetchRequest(
sortDescriptors: [NSSortDescriptor(keyPath: \MyObject.created, ascending: true)],
animation: .default)
private var myobjects: FetchedResults<MyObject>
var body: some View {
if self.myobjects.isEmpty{
Text("There are no objects in the current database.")
}
else{
// whatever
}
}
}