I have a N+1 problem which I cannot solve. I have a sample app hosted here that shows the issue: https://github.com/davidmles/question_parts
This is how it works:
There are 4 models: question, question_part, answer, and answer_part.
A question has N parts, and also N answers. An answer has N parts. And an answer part belongs to an answer and to a question part (the one is answering).
An answer can be a draft or published. A draft does not need to have all its parts answered, while a published answer does need them answered.
When an answer is created, but not all its parts are answered, and I try to publish it, validation will fail and the edit form will be shown again. When showing that edit form after validation failed, there will be a N+1 problem, as answer parts will load the corresponding question parts without eager loading them.
I have tried to eager load them, but then the edit form will not show the proper error.
How could I solve this? I have explained a bit better the problem in the app’s readme: https://github.com/davidmles/question_parts/blob/master/README.md