如何確認核心數據執行

Question

我想確認是否在覈心數據中的所有數據已經​​以下列源中刪除（其中「CoreDataHelper.getCoreDataHelper（）。上下文」的NSManagedObjectContext）

public static func delete(predicates: [NSPredicate] = []) { 
    let fetchRequest = request(predicates: predicates) 
    let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest) 
    do { 
     let result1 = try CoreDataHelper.getCoreDataHelper().context.fetch(fetchRequest) 
     NSLog("Delete batch size: %d", result1.count) 
     let result2 = try CoreDataHelper.getCoreDataHelper().context.execute(deleteRequest) 
     NSLog("Delete request succeeded: %d", result2) 
    } catch { 
     NSLog("Delete request failed") 
     return 
    } 
} 

當我1個

刪除請求成功：250432

測試它，以下是日誌

刪除批量大小所示

但是當我真正看到數據時，似乎沒有被刪除。 我嘗試添加一個數據，如下所示，數據已經存在於核心數據中。

public static func add(from object: Dictionary<String, Any>) -> NSManagedObjectProtocol? { 
    let exists = fetch(id: object) 
    if exists.count > 0 { 
     NSLog("Object already exists in CoreData : %@", object.description) 
     return nil 
    } else { 
     return newObject(object: object) as NSManagedObjectProtocol 
    } 
} 

對象已存在於CoreData：....

所以我的問題是我怎麼知道NSBatchDeleteRequest的是執行功能工作正常。是否有返回值可以用來確認執行過程中是否有錯誤？

Answer 1

保存您的NSManagedContext刪除後：

public static func delete(predicates: [NSPredicate] = []) { 
    let fetchRequest = request(predicates: predicates) 
    let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest) 
    do { 
     ... 
     let result2 = try CoreDataHelper.getCoreDataHelper().context.execute(deleteRequest) 
     //save context 
     try CoreDataHelper.getCoreDataHelper().context.save() 
    } catch { 
     NSLog("Delete request failed") 
     return 
    } 
}