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POIs there a use-case for singletons with database access in PHP?
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copied!<p>I access my MySQL database via PDO. I'm setting up access to the database, and my first attempt was to use the following:</p> <p>The first thing I thought of is <code>global</code>:</p> <pre><code>$db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'root', 'pwd'); function some_function() { global $db; $db->query('...'); } </code></pre> <p>This is considered a bad practice. After a little search, I ended up with the <a href="http://www.php.net/manual/en/language.oop5.patterns.php">Singleton pattern</a>, which</p> <blockquote> <p>"applies to situations in which there needs to be a single instance of a class." </p> </blockquote> <p>According to the example in the manual, we should do this:</p> <pre><code>class Database { private static $instance, $db; private function __construct(){} static function singleton() { if(!isset(self::$instance)) self::$instance = new __CLASS__; return self:$instance; } function get() { if(!isset(self::$db)) self::$db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'user', 'pwd') return self::$db; } } function some_function() { $db = Database::singleton(); $db->get()->query('...'); } some_function(); </code></pre> <p>Why do I need that relatively large class when I can do this?</p> <pre><code>class Database { private static $db; private function __construct(){} static function get() { if(!isset(self::$rand)) self::$db = new PDO('mysql:host=127.0.0.1;dbname=toto', 'user', 'pwd'); return self::$db; } } function some_function() { Database::get()->query('...'); } some_function(); </code></pre> <p>This last one works perfectly and I don't need to worry about <code>$db</code> anymore. </p> <p>How can I create a smaller singleton class, or is there a use-case for singletons that I'm missing in PHP?</p>

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