mysql> select count(*) from `information_schema`.`tables` where `table_schema` = 'table'; +----------+ | count(*) | +----------+ | 100 | +----------+ 1 row in set (0.01 sec) mysql> select count(*) from information_schema.columns where table_name = '#{テーブル名}'; +----------+ | count(*) | +----------+ | 158 | +----------+ 1 row in set (0.01 sec)