$mysql_pool

获取mysql连接池实例

例子：

    /**
     * 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();
    }