Rails 4 / postgresql - menyisipkan data pada tabel berdasarkan data tabel lain (after_create)

Sepertinya Anda salah ketik dalam kode Anda. Koneksi harus ActiveRecord::Base.connection tetapi Anda menulis DealPrize.connection.execute .

connection = ActiveRecord::Base.connection
connection.execute "sql query"

Coba ubah kode Anda seperti

after_create :create_deal_prizes

def create_deal_prizes
  Deal.transaction do
    connection = ActiveRecord::Base.connection
    self.prizes_number.times do |i|
      connection.execute "INSERT INTO ‘deal_prizes’ (deal_id) values (self.deal.id)"
    end
  end
end