"Connection Pool" using Static Class

I have an idea, but I'm not sure if it's possible

Using a static Class, that stores a static variable representing a mysql database connection. The file will be Pool.php

Then in DIFFERENT php files, say ClientA.php and ClientB.php

inside they would call

Pool::getConnection()

which returns a that single static mysql db connection.

Do static classes/variables work like this? That is, across files (with proper include statements in ClientA and ClientB)

 

Pool.php

class Pool
{
    
    protected $_dbConn;
    protected static $_instance = null;
    
    
    public function __construct() {
        // make a connection
    }
    
    public static function getDbConn()
    {
        return self::getInstance()->_dbConn;
    }

    public static function getInstance()
    {
        if (self::$_instance === null) {
            self::$_instance = new self();
        }
        
        return self::$_instance;
    }
}

PHP:

ClientA.php

// At some point Pool.php will need to be included
require_once 'Pool.php'

$dbConn = Pool::getDbConn();
// Do something

PHP:

 

Thanks! works like a charm

 

Make static class and static method to do dynamic request? Why so? You may do static request to property from static function.

class Pool
{
    protected $_dbConn = null;
   
    public static function getDbConn()
    {

        if (self::$_dbConn === null) {
//do connection
            self::$_dbConn = $connection_link; // save connection to link
        }

        return self::$_dbConn;
    }
}

PHP: