Warning: mysqli_connect(): MySQL server has gone away in /www/wwwroot/www/index.php on line 12

Warning: mysqli_connect(): Error while reading greeting packet. PID=1903 in /www/wwwroot/www/index.php on line 12

Warning: mysqli_connect(): (HY000/2006): MySQL server has gone away in /www/wwwroot/www/index.php on line 12
数据库连接失败：MySQL server has gone away