如果先调用connection.release()，就不会走return的代码，尝试使用try/catch/finally可以实现，但是感觉不好看，connection.release()是否有更优雅的使用方法，看文档定义是这样的，When you are done with a connection, just call connection.release() and the connection will return to the pool, ready to be used again by someone else.大家平时怎么处理release的？

		let connection = await mysqlPool.getConnection();
        let comment_count = await connection.query(sql, tid);
        console.log('mysql exec.');
        let count = comment_count[0]['count'];
        
        connection.release();
        return count;