I have used lightweight migration and there are no errors in loading the new store but when i fetch an entity i get an empty array. What could be the reason?
there is something worth considering. The old store had an entity A which had a relationship with entity B and C, both or which are no longer included in the new model. Just incase such a thing could be a issue.
Thanks. Neerav
Possible cause is that Xcode needs to be able to map old model on new model. So preparation is critical.
Is it the first time you experience the problem ? Did previous lightweight migrations work OK. These links may help (I don't know how much practice of Core Data migration you have)
https://developer.apple.com/documentation/coredata/using_lightweight_migration
h t t p s : / / w w w.raywenderlich.com/7585-lightweight-migrations-in-core-data-tutorial
Hope that helps.
This is the first time I am using lightweight migration and I am facing this issue. The returned array is empty. There are no errors.
_inferredMappingModelForSourceModel:destinationModel:error:; _ This method looks helpful. I can check in advance if the model can infer the new model. I need to make an NSURL to the path of the models in the project folder.
@"file:///Users/neeravkothari/Current Project/Expenses Pro v2/Expenses Pro/Expenses Pro/Model/Core Data/Expenses.xcdatamodeld/Expenses.xcdatamodel";
@"file:///Users/neeravkothari/Current Project/Expenses Pro v2/Expenses Pro/Expenses Pro/Model/Core Data/Expenses.xcdatamodeld/Expenses 2.xcdatamodel";
**Failed to load model as no file exists at path ** What is wrong with the path name?
Alight I checked the NSURL is loading file. Its in the next step that the code throws the error... when using initWithContentsOfURL method of the NSManagedObjectModel class. Further I get message (zero byte file) which i checked through Finder, isn't true.
