Not getting To-Many Relationship in Core Data - ios

Question

I am trying to understand Core Data (To-Many) relationship. In the following code, I have two Entities
PeopleList <-->> TransactionDetails
NSManagedObjectContext *context = [self managedObjectContext];
NSManagedObject *personDetails = [NSEntityDescription
insertNewObjectForEntityForName:#"PeopleList"
inManagedObjectContext:context];
[personDetails setValue:[person fullName] forKey:#"name"];
NSManagedObject *transactionDetails = [NSEntityDescription
insertNewObjectForEntityForName:#"TransactionDetails"
inManagedObjectContext:context];
[transactionDetails setValue:[NSNumber numberWithFloat:oweAmount] forKey:#"amount"];
NSError *error;
if (![context save:&error]) {
NSLog(#"Whoops, couldn't save: %#", [error localizedDescription]);
}
Now this code inserts a New Object (row) to the model. What I am confused with is:
1. Don't I have to write code for relating object values in two Entities (PeopleList and TransactionDetails)?
2. If I run this code again and again, It just keep on adding same object in first Entity (PeopleList). How to write for To-Many relationship? What I can get from last few hours of reading is I have to fetch the results, search for that particular object and if it exist then dont insert a new object with same name. But in that case, how will it relate the two entities.

Answer 1

Are your model entities correctly wired in the model editor as far as the to-many relationship is concerned? Have you generated the class files for your entities? If you can answer both questions with yes you create a personlist entity as you did and the details entity too but you need to the details to your personlist. Have a look into the class files for the method name(s).

Answer 2

It won't, because you're not setting the relationships on either of your objects. I don't see where you're setting the PeopleList property of your newly minted TransactionDetail object (sorry, I don't know how you've got the properties named in your model, so I'm just using the class names). So, after creating your transactionDetails object, you'd need to do something like transactionDetails.PeopleList = personDetails, and both relationships would be set at that point; transactionDetails.PeopleList property would point to your personDetails object, and personDetails.TransactionDetails set would contain transactionDetails.
What is your person object, that you're using to set the name from?
On another note, you might want to consider moving all this sort of stuff into subclasses of NSManagedObject; write your own super easy constructors/initializers, etc, for each of your entities. Lots of people never do this, and end up littering their controller code with lots of CoreData boiler plate, which is a mystery to me, because it's what makes using CoreData so nice.