Bulk Updatable

bulk_updatable.rb

module BulkUpdatable
  extend ActiveSupport::Concern

  class_methods do
    def bulk_update(attributes)
      return true if attributes.empty?

      attrs = attributes.map { |attribute| attribute.to_h.symbolize_keys }
      fields = attrs.first.keys.map(&:to_sym) - [:id]

      sql = "UPDATE `#{table_name}` SET\n"
      sql << fields.map do |field|
        value_def = attrs.map do |attribute|
          "WHEN #{connection.quote(attribute[:id])} THEN #{connection.quote(attribute[field])}"
        end.join("\n")
        "`#{table_name}`.`#{field}` = CASE `#{table_name}`.`id`\n#{value_def}\nEND"
      end.join(",\n")
      sql << "\nWHERE `#{table_name}`.`id` IN (#{attrs.pluck(:id).join(',')})"

      transaction do
        connection.execute(sql)
      end
    end
  end
end