How to identify Rails 6 bulk insert error - ruby-on-rails

Question

I have the following relations set up:
user has_many quizzes
quiz belongs_to user
quiz has_many questions
question belongs_to quiz
App is set up to use PostgreSQL. I'm trying to bulk insert a bunch of records using the insert_all! method
begin
quiz = user.quizzes.create!(title: title, slug: slug)
quiz_questions = params[:quiz][:questions].map! do |q|
# creating an attribute hash here (code removed for conciseness of question)
end
result = quiz.questions.insert_all!(quiz_questions)
This threw an error which was caught by my "catch all" block
rescue ActiveRecord::ActiveRecordError
render json: { message: ['Something went wrong'] }, status: 500
The running server console printed this message:
TRANSACTION (0.9ms) BEGIN
↳ app/controllers/quizzes_controller.rb:14:in `create'
Quiz Create (2.8ms) INSERT INTO "quizzes" ("title", "user_id", "slug", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id" [["title", "a quiz"], ["user_id", 1], ["slug", "a-quizk2DqYk"], ["created_at", "2021-12-01 05:00:05.800134"], ["updated_at", "2021-12-01 05:00:05.800134"]]
↳ app/controllers/quizzes_controller.rb:14:in `create'
TRANSACTION (1.6ms) COMMIT
↳ app/controllers/quizzes_controller.rb:14:in `create'
Question Bulk Insert (0.6ms) INSERT INTO "questions" ("question","a","b","c","d","score","answer","quiz_id") VALUES ('what is name', 'str', 'char', 'num', 'bool', 5, 'A', 1), ('die', 'yes', 'no', 'ok', 'what', 5, 'B', 1) RETURNING "id"
↳ (eval):6:in `block in insert_all!'
Completed 500 Internal Server Error in 153ms (Views: 0.2ms | ActiveRecord: 38.1ms | Allocations: 49609)
So I think I am not calling insert_all! correctly because the server just does an insert without the BEGIN and COMMIT bookends. Also, I would like to know which error is being thrown and caught by the catch all block. What would be the correct way to do insert_all! ?

Answer 1

you could wrap your bulk insert into a transaction
def bulk_insert
ActiveRecord::Base.transaction do
quiz = user.quizzes.create!(title: title, slug: slug)
quiz_questions = params[:quiz][:questions].map! do |q|
# creating an attribute hash here
# ...
# note that you could validate attribute manually
raise ActiveRecord::Rollback if q.description.blank?
end
result = quiz.questions.insert_all!(quiz_questions)
end
rescue ActiveRecord::Rollback => e
puts e
end