defined PHP connection to the database under IIS prompts mysql undefined function mysql_connect

1.
Remove the ";" in front of the following parameters in PHP.ini:

Copy the code The code is as follows:

;extension=php_dba.dll
;extension=php_gd2.dll
;extension= php_mbstring.dll
;extension=php_mcrypt.dll
;extension=php_mysql.dll
;extension=php_mysqli.dll
;extension=php_pdo.dll
;extension=php_pdo_mysql.dll

Save the file and restart IIS
Specific instructions
In php.ini, change
;extension=php_mysql.dll
to
extension=php_mysql.dll
extension_dir = " "
Change to
extension_dir = "ext/"
Copy libmysql.dll to system32 and finally restart Just
test whether php mysql can connect
$link=mysql_connect( 'localhost ', 'root ', '123456 ');
if(!$link) echo "fail ";
else echo "success ";
mysql_close();
?>
2.
1.php_info() Check if there is a mysql item (search for the "mysql" keyword). If so, it may be a version compatibility issue
2. If not Copy libmysql.dll in the php file to x:windowssystem32. Remove the comment of the mysql module in php.ini with extension=php_mysql.dll. Restart apache. If it still doesn’t work, restart the machine and try to test using the php_info() function.
Right-click My Computer->Properties->Advanced->Environment Variables->System Environment Variables
a. Select Path in "System Environment Variables" to highlight this line, and then select "Edit" , add ";D:php" (the directory where php.exe is located) at the end of the variable value
b. "System Environment Variables"->"New"->Variable name "PHPRC"->Variable value "D :php" (the directory where php.ini is located) ->
2. Check that the PhpIniDir setting in the httpd.conf file points to the directory of Php.
3. Try to change PhpIniDir="C:/Php" in httpd.conf to PhpIniDir="C:Php".

The above introduces the defined mysql undefined function mysql_connect prompt for PHP connection to the database under IIS, including the defined content. I hope it will be helpful to friends who are interested in PHP tutorials.