gistfile1.txt

module ActiveRecord
  class Base
    # Define a method that can be called on an ActiveRecord::Base class
    # or on a Scope object. This will call the db-adapters select_and_yield
    # to perform the query and yield back each row found. Each row is then
    # instantiated into an object and yielded to the caller.
    def self.yield_all(*args)
      raise "Must supply block" unless block_given?

      options = args.extract_options!
      validate_find_options(options)
      set_readonly_option!(options)

      sql = construct_finder_sql(options)

      connection.select_and_yield(sanitize_sql(sql), "#{name} Load") do |record|
        record.readonly! if options[:readonly] && record.respond_to?(:readonly)
        object = instantiate(record)

        yield object
      end
    end
  end

  module ConnectionAdapters
    module DatabaseStatements
      def yield_all(sql, name = nil)
        select_and_yield(sql, name)
      end
    end

    class JdbcAdapter < AbstractAdapter
      def select_and_yield(sql, name = nil)
        select(sql, name).each do |row|
          yield row
        end
      end
    end

    MYSQL_SUPERCLASS = defined?(JRuby) ? JdbcAdapter : AbstractAdapter

    class MysqlAdapter < MYSQL_SUPERCLASS
      def select_and_yield(sql, name = nil)
        if @connection.respond_to?(:query_with_result)
          @connection.query_with_result = true
        end

        result = execute(sql, name)

        if @connection.respond_to?(:query_with_result)
          result.each_hash do |row|
            yield row
          end
        else
          result.each do |row|
            yield row
          end
        end
      ensure
        result.free if result.respond_to?(:free)
      end
    end
  end
end