php mysqli 不能连接mysql.sock

Message: mysqli_connect(): (HY000/2002): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)



我在命令行 mysql -uroot -p -S/var/lib/mysql/mysql.sock 是可以连上的

---

// By UNIX Domain Socket
$mysqli = @new mysqli(
    null, 
    $app['db_username'], 
    $app['db_password'], 
    $app['db_name'], 
    null, 
    $app['db_socket']
);

// By TCP Port
$mysqli = @new mysqli(
    $app['db_host'], 
    $app['db_username'], 
    $app['db_password'], 
    $app['db_name'], 
    $app['db_port']
);