# $mysql_pool 获取mysql连接池实例 例子： ```php /** * mysql Replace 命令 */ public function testMysqlReplace() { $value = yield $this->mysql_pool->dbQueryBuilder->replace('MysqlTest') ->set('firstname', 'White') ->set('lastname', 'Cat') ->set('age', '26') ->set('townid', '10000')->coroutineSend(); $this->destory(); } ```