hasTable('maintenance_mapper')) { $table = $this->table('maintenance_mapper'); $table->addColumn('fan_model', 'string', ['limit' => 32, 'null' => true, 'signed' => true, 'comment' => '风机型号',]) ->addColumn('parts', 'string', ['limit' => 255, 'null' => true, 'signed' => true, 'comment' => '部件',]) ->update(); } } }