Question

我尝试从coredata中删除一行。我处理这行但我没有删除。当我尝试 context.delete（）它需要（）中的 NSManagedObject 。我如何将此结果转换为NSManagedObject？

func deleteElement(postUid:String){

    let appDel:AppDelegate = (UIApplication.shared.delegate as! AppDelegate)
    let context:NSManagedObjectContext = appDel.persistentContainer.viewContext

    let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Posts")
    let predicate = NSPredicate(format: "postUid == %@", postUid as CVarArg)
     fetchRequest.predicate = predicate

    do {

        let result = try context.fetch(fetchRequest)

        print("Result \(result)")



        try context.save()

    } catch {
        print("Error \(error)")
    }

}

//结果打印

Result [<Posts: 0x6080002901d0> (entity: Posts; id: 0xd000000000640000 <x-coredata://9A330E28/Posts/p25> ; data: {
item = "<relationship fault: 0x60c00022b900 'item'>";
lastMessageTime = "2018-05-23";
parentUid = nil;
postUid = "15e43d16";
title = Title;
userUid = ".."; })]

Answer 1

let result = try context.fetch(request)
for object in result {
    let obj = object as! NSManagedObject
    context.delete(obj)
}

try context.save()

您基本上需要获取对象，然后逐个删除它们。然后你就像往常一样保存上下文。

Swift - 删除CoreData行

1 个答案: