In order to create relation between custom tables you can use parentID field. To understand how it works let’s look through the following example:
let’s say you have two entities - Movies and Comments.
Each comment has parentID = movieID.
If you delete this movie, all comments will be deleted as well.
To get related records you can just use extendedRequest param, like in the following sample:
NSMutableDictionary *getRequest = [NSMutableDictionary dictionary]; [getRequest setObject:@"31212412a1269123" forKey:@"_parent_id"]; [QBCustomObjects objectsWithClassName:@"Comment" extendedRequest:getRequest delegate:self];