Drupal, php.ini and Call to undefined function mysqli_real_escape_string error

I've a Drupal website no Windows IIS on godaddy.

I've changed the php memory_limit using a root directory level php.ini file (from 32M to 64M).

However, when I run Drupal (in a subfolder) I get the following error:

Fatal error: Call to undefined function mysqli_real_escape_string() in D:\Hosting\3790877\html\fuzion\includes\database.mysqli.inc on line 330

If I remove the php.ini file, drupal runs correctly.

What's the issue ? thanks

check if you have mysqli extension enabled at all in your php.ini.You do need php5 to get the mysqli extension and that extension must be enabled.The error means that the mysqli extension is not enabled in php

Here are the php.ini lines that you need to check for-

extension=php_mysqli.dll

[MySQLi]

; Maximum number of links.  -1 means no limit.
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.
mysqli.default_port = 3306

; Default socket name for local MySQL connects.  If empty, uses the built-in
; MySQL defaults.
mysqli.default_socket =

; Default host for mysql_connect() (doesn't apply in safe mode).
mysqli.default_host =

; Default user for mysql_connect() (doesn't apply in safe mode).
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.
mysqli.default_pw =

; Allow or prevent reconnect
mysqli.reconnect = Off

[mSQL]
; Allow or prevent persistent links.
msql.allow_persistent = On

; Maximum number of persistent links.  -1 means no limit.
msql.max_persistent = -1

; Maximum number of links (persistent+non persistent).  -1 means no limit.
msql.max_links = -1

edit them acc. to your requirements.

Regarding your other question about the main php.ini and php.ini in other sub directories see this and this