php - Fatal error: Call to undefined function mysqli_connect() while extension are set properly -

I searched in "google", but I have not found a right answer. I have also seen many questions in "Stackoverflow" but they do not describe my problem.

And these two questions are close to my problem, but they are not solving my problem, anyway I have a problem:

I did not have the php Code that will connect to my mysql database server.

  & lt ;? Php echo "enter db"; $ Link = mysqli_connect ('localhost', 'root', 'qwerty'); Echo "enter"; ? & Gt;   
  Note:   
 I have edited  
 
 extension_dir = "C: \ PHP \ ext " 
 Extension = php_mysqli.dll  
 
 The result of  
 ini_set ('display_errors', 1); Error_Reporting (E_ALL) **; Same is ** Fatal Error: Call for mysqli_connect ()   
 
 Undefined function I have performed the echo 'ini:', get_cfg_var ('cfg_file_path') ;  and its  C: \ PHP \ php.ini     
 I use  Apache 2.2.11  I am doing and  PHP 5.2.17  and  MySQL 5.5  Anyone have any ideas, what is wrong?  
 
 And in the "PHP_MYSQLI.DLL" EXT folder.   
  Edit:  There is no information about the database server in surprisingly  phpinfo () . Someone tells me what's the problem:  Edit 2:   
   Anyone who wants to download non-thread safe or thread safe .. I have no thread safe I have not downloaded     
 
 
 I do not know whether it will help others or No .. But still I am giving this answer because I did not get any proper solution here.I have tried to check all the error and I am sure That there was no mistake in my code. And as I said all the extensions were properly loaded I was not an appropriate solution. And  wamp