php无法连接mysqli怎么办

[MySQLi]

; Maximum number of persistent links. -1 means no limit.
; http://php.net/mysqli.max-persistent
mysqli.max_persistent = -1

; Allow accessing, from PHP’s perspective, local files with LOAD DATA statements
; http://php.net/mysqli.allow_local_infile
;mysqli.allow_local_infile = On

; Allow or prevent persistent links.
; http://php.net/mysqli.allow-persistent
mysqli.allow_persistent = On

; Maximum number of links. -1 means no limit.
; http://php.net/mysqli.max-links
mysqli.max_links = -1

; Default port number for mysqli_connect(). If unset, mysqli_connect() will use
; the $MYSQL_TCP_PORT or the mysql-tcp entry in /etc/services or the
; compile-time value defined MYSQL_PORT (in that order). Win32 will only look
; at MYSQL_PORT.
; http://php.net/mysqli.default-port
mysqli.default_port = 3306

; Default socket name for local MySQL connects. If empty, uses the built-in
; MySQL defaults.
; http://php.net/mysqli.default-socket
mysqli.default_socket =

; Default host for mysqli_connect() (doesn’t apply in safe mode).
; http://php.net/mysqli.default-host
mysqli.default_host =

; Default user for mysqli_connect() (doesn’t apply in safe mode).
; http://php.net/mysqli.default-user
mysqli.default_user =

; Default password for mysqli_connect() (doesn’t apply in safe mode).
; Note that this is generally a bad idea to store passwords in this file.
; Any user with PHP access can run 'echo get_cfg_var(“mysqli.default_pw”)
; and reveal this password! And of course, any users with read access to this
; file will be able to reveal the password as well.
; http://php.net/mysqli.default-pw
mysqli.default_pw =

; Allow or prevent reconnect
mysqli.reconnect = OFF