如何在Swift3中向实体插入新数据? [英] How to insert new data to entity in Swift3?

问题描述

以前，我能够使用这样的代码将新数据添加到我的数据模型中的"TestEntity"中.

In swift previously, I was able to use a code like this to add new data to my "TestEntity" in my data model.

NSManagedObject是为我的"TestEntity"创建的，我能够使用点"语法设置其属性

NSManagedObject was created for my "TestEntity" and I was able to set its attributes with the "dot" syntax

最后，我要保存上下文

let entity=NSEntityDescription.insertNewObject(forEntityName: "TestEntity", into: context) as! TestEntity
entity.testAttribute="test value"
context.save()

此代码在Swift3中不起作用.当我运行它时，出现以下运行时错误:

This code does not work in Swift3. When I run it, i get the following runtime error:

无法转换类型为'NSManagedObject_TestEntity_'的值 (0x175306b0)到'testCoreData.TestEntity'(0xd6bb8). 2016-06-19 11:07:52.305195 testCoreData [689:264453]无法转换类型的值 将'NSManagedObject_TestEntity_'(0x175306b0)更改为 'testCoreData.TestEntity'(0xd6bb8)

Could not cast value of type 'NSManagedObject_TestEntity_' (0x175306b0) to 'testCoreData.TestEntity' (0xd6bb8). 2016-06-19 11:07:52.305195 testCoreData[689:264453] Could not cast value of type 'NSManagedObject_TestEntity_' (0x175306b0) to 'testCoreData.TestEntity' (0xd6bb8)

请问有人可以在swift3中完成此操作吗?任何帮助都将受到高度赞赏. 谢谢.

Can anyone shed some light on how this should be done in swift3, please? Any help is highly appreciated. Thank you.

问题的第二部分是如何再次访问数据.以下代码以错误结尾:致命错误:NSArray元素与Swift Array元素类型不匹配

The second part of the question is how to access the data again. the following code ends with an error: fatal error: NSArray element failed to match the Swift Array Element type

let fr:NSFetchRequest<TestEntity>=TestEntity.fetchRequest()

do {
   let searchResults=try context.fetch(fr)
   if let results=searchResults {
      for result in results {
         print("testAtt = \(result.testAtt)")
      }
   }
} catch {

}

推荐答案

如果存在NSManagedObject子类TestEntity，则新语法为

If there is a NSManagedObject subclass TestEntity the new syntax is

let entity = TestEntity(context: context)
entity.testAttribute="test value"

这篇关于如何在Swift3中向实体插入新数据?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！