copy_table_contents

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 451
        def copy_table_contents(from, to, columns, rename = {})
          column_mappings = Hash[columns.map { |name| [name, name] }]
          rename.each { |a| column_mappings[a.last] = a.first }
          from_columns = columns(from).collect(&:name)
          columns = columns.find_all { |col| from_columns.include?(column_mappings[col]) }
          from_columns_to_copy = columns.map { |col| column_mappings[col] }
          quoted_columns = columns.map { |col| quote_column_name(col) } * ","
          quoted_from_columns = from_columns_to_copy.map { |col| quote_column_name(col) } * ","

          exec_query("INSERT INTO #{quote_table_name(to)} (#{quoted_columns})
                     SELECT #{quoted_from_columns} FROM #{quote_table_name(from)}")
        end