Swift-同时访问核心数据中的多个实体

Question

I'm saving objects to my core data, and now I need to save data to two different entities at once. Following my own logic, if I normally save my data like this (which works perfectly):

    let appDel: AppDelegate = UIApplication.sharedApplication().delegate as AppDelegate
    let contxt: NSManagedObjectContext = appDel.managedObjectContext!
    let en = NSEntityDescription.entityForName("MainTable", inManagedObjectContext: contxt)

        var newMessage = SecondModel(entity: en!, insertIntoManagedObjectContext: contxt)
            newMessage.receiver = object["Receiver"] as String

contxt.save(nil)

I should be able to save to another entity by creating another variable with my different entity like this:

let enet = NSEntityDescription.entityForName("AlreadyRec", inManagedObjectContext: contxt)
var secondMessage = ThirdModel(entity: enet!, insertIntoManagedObjectContext: contxt)

This gives me the error saying the "ThirdModel has no available initializers, and I don't know what this means or how to solve this issue. Please help me solve this problem.

Any suggestions on how to proceed would be highly appreciated.

Answer 1

Your context covers all of Core Data. Just save at the end.

1. create / edit entity1
2. create / edit entity2
3. save

Some advice: get away from your nondescript naming conventions. Don't call your entity MainTable - that does not even make sense in the SQL world! To my horror I noticed that your managed object model subclass is not called MainTable but SecondModel .

If your data describes widgets, you should call your entity and its subclass Widget . If it is something abstract, such as programming habits, you could call it Habit . Get the point?