Swift - 删除CoreData行[重复]

Posted 2023-03-05

【中文标题】Swift - 删除CoreData行[重复]

【英文标题】：Swift - Delete CoreData row [duplicate]

【发布时间】：2018-05-23 14:28:18

【问题描述】：

我尝试从 coredata 中删除一行。我处理了这一行，但我没有删除。当我尝试 context.delete() 时，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 = ".."; )]

【参考方案1】：

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


try context.save()

你基本上需要获取你的对象，然后一个接一个地删除它们。然后你像往常一样保存你的上下文。