PDO File not found on seven year old app....

Hi Folks - I have a php application that I wrote six years ago from scratch. I haven't touched the code base for at least four years and it has been running as expected. It is now giving me a 500 error with the message:

HP Fatal error:  Uncaught Error: Class "PDO" not found in public_html/rhschoirs.net/dbs/db.php:120

Line 120 of this file is:

private function connect_To_My_Sql_Database()
    {
       static $db = NULL;

       //if no database connection has been made, 
       //establish a database connection
       if(is_null($db)){
            
            $dbname = 'rhs********'; 
            
            if(self::$environment === 'production'){

                /*** PRODUCTION ***********/
                $user = 'rhs****';
                $pw = '************';
                $host = 'localhost';
                
            }else{
                
                //user is in the test system
                $user = 'rhs*****;		
                $pw = *************';	
                $host = 'localhost';
            }
            
            try{

                $db = new \PDO("mysql:host=$host;dbname=$dbname",$user,$pw);				

            }catch(PDOException $e){

                //catch for test system
                self::addLog(__FILE__,__CLASS__,__METHOD__,__LINE__,$e);

                $db=FALSE;

            }
       }

       return $db; 
   }

I'm now searching for an old backup copy to test on and I've tried to just drop in a copy of PDO.php from the php site into the /dbs directory but that didn't change anything. Any thoughts on this are appreciated! Rick

LaryAI

1 year ago

Level 58

It looks like your PHP application is throwing a fatal error because it cannot find the PDO class. This typically happens when the PDO extension is not enabled in your PHP configuration. Here are the steps you can take to resolve this issue:

Check if PDO is installed and enabled:
- Create a PHP file (e.g., phpinfo.php) with the following content:
```
<?php
phpinfo();
?>
```
- Access this file through your web browser. Look for a section titled PDO. If you don't see it, then PDO is not enabled.
Enable the PDO extension:
- Open your php.ini file. The location of this file can vary depending on your server setup. Common locations include /etc/php.ini, /etc/php/7.4/apache2/php.ini, or /etc/php/7.4/cli/php.ini.
- Look for the following lines and make sure they are not commented out (remove the ; at the beginning of the line if it exists):
```
extension=pdo.so
extension=pdo_mysql.so
```
- If these lines are not present, add them.
Restart your web server:
- After making changes to php.ini, you need to restart your web server for the changes to take effect. The command to restart the server depends on the server software you are using. For example:
  - For Apache:
```
sudo systemctl restart apache2
```
  - For Nginx with PHP-FPM:
```
sudo systemctl restart php7.4-fpm
sudo systemctl restart nginx
```
Verify the changes:
- Reload the phpinfo.php file in your browser and check if the PDO section is now present.
Check for syntax errors:
- Ensure there are no syntax errors in your db.php file. The code you posted seems to have a typo in the test system credentials:
```
$user = 'rhs*****'; // Correct the typo here
$pw = '*************'; // Correct the typo here
```

Here is the corrected version of your connect_To_My_Sql_Database function:

private function connect_To_My_Sql_Database()
{
    static $db = NULL;

    // if no database connection has been made, 
    // establish a database connection
    if (is_null($db)) {
        $dbname = 'rhs********';

        if (self::$environment === 'production') {
            /*** PRODUCTION ***********/
            $user = 'rhs****';
            $pw = '************';
            $host = 'localhost';
        } else {
            // user is in the test system
            $user = 'rhs*****';
            $pw = '*************';
            $host = 'localhost';
        }

        try {
            $db = new \PDO("mysql:host=$host;dbname=$dbname", $user, $pw);
        } catch (PDOException $e) {
            // catch for test system
            self::addLog(__FILE__, __CLASS__, __METHOD__, __LINE__, $e);
            $db = FALSE;
        }
    }

    return $db;
}

By following these steps, you should be able to resolve the Class "PDO" not found error and get your application running again.