假设你正在使用MagicalRecord并且有一个默认的持久性存储:

我不喜欢所有假设存在特定文件和/或要求输入实体名称或类的解决方案。这是一个Swift(2)，安全的方式删除所有实体的所有数据。删除后，它将重新创建一个新的堆栈(我实际上不确定这部分是多么必要)。

这是godo的“注销”风格的情况下，当你想删除一切，但有一个工作的存储和moc，以获得新的数据(一旦用户登录…)

extension NSManagedObject {

    class func dropAllData() {

        MagicalRecord.saveWithBlock({ context in

            for name in NSManagedObjectModel.MR_defaultManagedObjectModel().entitiesByName.keys {
                do { try self.deleteAll(name, context: context) }
                catch { print("⚠️ ✏️ Error when deleting \(name): \(error)") }
            }

            }) { done, err in
                MagicalRecord.cleanUp()
                MagicalRecord.setupCoreDataStackWithStoreNamed("myStoreName")
        }
    }

    private class func deleteAll(name: String, context ctx: NSManagedObjectContext) throws {
        let all = NSFetchRequest(entityName: name)
        all.includesPropertyValues = false

        let allObjs = try ctx.executeFetchRequest(all)
        for obj in allObjs {
            obj.MR_deleteEntityInContext(ctx)
        }

    }
}

这个问题有几个很好的答案。这里有一个简洁的例子。前两行删除sqlite数据库。然后for:循环删除managedObjectContext内存中的任何对象。

NSURL *storeURL = [[(FXYAppDelegate*)[[UIApplication sharedApplication] delegate] applicationDocumentsDirectory] URLByAppendingPathComponent:@"AppName.sqlite"];
[[NSFileManager defaultManager] removeItemAtURL:storeURL error:nil];
for (NSManagedObject *ct in [self.managedObjectContext registeredObjects]) {
    [self.managedObjectContext deleteObject:ct];
}

iOS 10 + Swift 3解决方案:

func clearCoreDataStore() {
    let delegate = UIApplication.shared.delegate as! AppDelegate
    let context = delegate.persistentContainer.viewContext

    for i in 0...delegate.persistentContainer.managedObjectModel.entities.count-1 {
        let entity = delegate.persistentContainer.managedObjectModel.entities[i]

        do {
            let query = NSFetchRequest<NSFetchRequestResult>(entityName: entity.name!)
            let deleterequest = NSBatchDeleteRequest(fetchRequest: query)
            try context.execute(deleterequest)
            try context.save()

        } catch let error as NSError {
            print("Error: \(error.localizedDescription)")
            abort()
        }
    }
}

遍历所有核心数据实体并清除它们

似乎有两种方法:

假设您的核心数据堆栈有一个典型的单例。

import CoreData
public let core = Core.shared
public final class Core {
    static let shared = Core()
    var container: NSPersistentContainer!
    private init() {
        container = NSPersistentContainer(name: "stuff")
        //deleteSql()
        container.loadPersistentStores { storeDescription, error in
            if let error = error { print("Error loading... \(error)") }
        }
        //deleteAll()
    }
    
    func saveContext() { // typical save helper
        if container.viewContext.hasChanges {
            do { try container.viewContext.save()
            } catch { print("Error saving... \(error)") }
        }
    }
    

然后……

    func deleteSql() {
        let url = FileManager.default.urls(
           for: .applicationSupportDirectory,
           in: .userDomainMask)[0].appendingPathComponent( "stuff.sqlite" )
        
        guard FileManager.default.fileExists(atPath: url.path) else {
            print("nothing to delete!")
            return
        }
        
        do {
            try container.persistentStoreCoordinator.destroyPersistentStore(
                at: url, ofType: "sqlite", options: nil)
            print("totally scorched the sql file. you DO now have to LOAD again")
        }
        catch {
            print("there was no sql file there!")
        }
    }
    
    func deleteAll() { // courtesy @Politta
        for e in container.persistentStoreCoordinator.managedObjectModel.entities {
            let r = NSBatchDeleteRequest(
              fetchRequest: NSFetchRequest(entityName: e.name ?? ""))
            let _ = try? container.viewContext.execute(r)
        }
        saveContext()
        print("conventionally deleted everything from within core data. carry on")
    }
}

.

1. 焦化SQL文件

感谢优秀的@J。能源部的答案。您完全销毁了sql文件。

你必须这样做

在加载核心数据之前，即在创建容器之后，但是 在真正载入商店之前。)

(注意示例代码“//deleteSql()”就在初始化之前。)

2. 逐个删除核心数据中的所有内容

感谢精彩的@Politta回答。一旦core data启动并运行，就可以随时执行此操作。

(注意示例代码“//deleteAll()”是在初始化之后。)

方法一在开发过程中可能更有用。方法二在生产中可能更有用(在相对不常见的情况下，由于某种原因需要擦除所有内容)。

Swift 5.1解决方案

public static func reset() {
    let coordinator = _persistentContainer.persistentStoreCoordinator
    for store in coordinator.persistentStores where store.url != nil {
        try? coordinator.remove(store)
        try? FileManager.default.removeItem(atPath: store.url!.path)
    }
}

下面这个版本可以删除每个表中的每条记录。

斯威夫特4

static func resetDatabase() {
    do {
        try dataStore.persistentStoreCoordinator.managedObjectModel.entities.forEach { (entity) in
            if let name = entity.name {
                let fetch = NSFetchRequest<NSFetchRequestResult>(entityName: name)
                let request = NSBatchDeleteRequest(fetchRequest: fetch)
                try mainContext.execute(request)
            }
        }

        try mainContext.save()
    } catch {
        print("error resenting the database: \(error.localizedDescription)")
    }
}