延续戴夫·德隆的回答。

Swift版本，照顾iOS 9和以前的版本以及。我还介绍了错误处理:

let appDelegate： AppDelegate = UIApplication.sharedApplication（）.delegate as！应用委托

    let fetchRequest = NSFetchRequest(entityName: "Car")
    if #available(iOS 9.0, *) {
        let delete = NSBatchDeleteRequest(fetchRequest: fetchRequest)
        do {
            try appDelegate.persistentStoreCoordinator.executeRequest(delete, withContext: appDelegate.managedObjectContext)
        } catch let error as NSError {
            print("Error occured while deleting: \(error)")
        }
    } else {
        // Fallback on earlier versions
        let carRequest = NSFetchRequest()
        carRequest.entity = NSEntityDescription.entityForName("Cars", inManagedObjectContext: appDelegate.managedObjectContext)
        carRequest.includesPropertyValues = false

        do {
            let cars: NSArray = try appDelegate.managedObjectContext.executeFetchRequest(carRequest)

            for car in cars {
                appDelegate.managedObjectContext.delete(car)
            }

            try appDelegate.managedObjectContext.save()

        } catch let error as NSError {
            print("Error occured while fetching or saving: \(error)")
        }
    }

快速清除DB中的所有对象:

func purgeAllData() {
    let uniqueNames = persistentContainer.managedObjectModel.entities.compactMap({ $0.name })

    uniqueNames.forEach { (name) in
      let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: name)
       let batchDeleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)
         do {
        try persistentContainer.viewContext.execute(batchDeleteRequest)
      } catch {
        let nserror = error as NSError
        fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
      }
   }
 }

在Swift 2.0中:

func deleteAllData(entity: String)
{
    let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
    let managedContext = appDelegate.managedObjectContext
    let fetchRequest = NSFetchRequest(entityName: entity)
    fetchRequest.returnsObjectsAsFaults = false

    do 
    {
        let results = try managedContext.executeFetchRequest(fetchRequest)
        for managedObject in results
        {
            let managedObjectData:NSManagedObject = managedObject as! NSManagedObject
            managedContext.deleteObject(managedObjectData)
        }
    } catch let error as NSError {
        print("Detele all data in \(entity) error : \(error) \(error.userInfo)")
    }
}

NSBatchDeleteRequest Swift 5.5和Xcode 13.2

删除SQLite持久存储中的对象，而不加载到内存中。在持久存储上执行的更改不会反映在当前内存中的对象中。

执行批量删除之后，从持久存储中删除内存中的所有对象。

下面是执行batchDeleteRequest的一些方便的扩展方法

extension NSManagedObject {
    
    private static var entityName: String {
        return String(describing: self)
    }
    
    static func fetchRequest<Self>(
        with predicate: NSPredicate? = nil,
        configureBlock: ((NSFetchRequest<Self>) -> Void)? = nil
    ) -> NSFetchRequest<Self> where Self: NSFetchRequestResult {
        let request = NSFetchRequest<Self>(entityName: entityName)
        request.predicate = predicate
        configureBlock?(request)
        return request
    }
    
    static func batchDelete(with fetchRequest: NSFetchRequest<NSFetchRequestResult>,
                            in context: NSManagedObjectContext) {
        let batchDeteleRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)
        batchDeteleRequest.resultType = .resultTypeObjectIDs
        do {
            if let fetchResult = try context.execute(batchDeteleRequest) as? NSBatchDeleteResult,
               let deletedManagedObjectIds = fetchResult.result as? [NSManagedObjectID], !deletedManagedObjectIds.isEmpty {
                let changes = [NSDeletedObjectsKey: deletedManagedObjectIds]
                NSManagedObjectContext.mergeChanges(fromRemoteContextSave: changes, into: [context])
            }
        } catch {
            print("Error while executing batchDeleteRequest: \(error.localizedDescription)")
        }
    }
}

示例:我们可以通过传递fetchRequest调用batchDelete静态方法批量删除实体

class Entity: NSManagedObject {
    @NSManaged var name: String?
    @NSManaged var value: String?
}

extension Entity {
    
    static func executeBatchDelete(in context: NSManagedObjectContext) {
        let predicate = NSPredicate(format: "\(#keyPath(Entity.value)) == %@)", "abc")
        let deleteRequest: NSFetchRequest<NSFetchRequestResult> = Entity.fetchRequest(with: predicate)
        Entity.batchDelete(with: deleteRequest, in: context)
    }
}

对于Swift 2.0:

class func clearCoreData(entity:String) {
  let fetchRequest = NSFetchRequest()
  fetchRequest.entity = NSEntityDescription.entityForName(entity, inManagedObjectContext: moc!)
  fetchRequest.includesPropertyValues = false
  do {
    if let results = try moc!.executeFetchRequest(fetchRequest) as? [NSManagedObject] {
      for result in results {
        moc!.deleteObject(result)
      }

      try moc!.save()
    }
  } catch {
    LOG.debug("failed to clear core data")
  }
}

Dave Delongs的Swift 2.0回答让我崩溃了(在iOS 9中)

但这个方法奏效了:

let fetchRequest = NSFetchRequest(entityName: "Car")
let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)

    do {
        try managedObjectContext.executeRequest(deleteRequest)
        try managedObjectContext.save()
    }
    catch let error as NSError {
       // Handle error
    }