PHP：以靜態方法連接到數據庫

Question

我想添加一個靜態方法到我的類，它連接到我的數據庫並返回一個數組數組。例如，我有一個名爲Users的表和一個名爲User的類，我希望能夠調用$ user = User :: fetch（$ id）來獲取指定用戶信息的數組。所以我的問題是，何時何地應該連接到數據庫？每次我調用用於類似目的的靜態方法時，是否需要傳遞數據庫連接信息？那只是感覺不對。

Answer 1

我做的是有一個非常早期的火一個的ConnectionManager類連接到相關數據庫但應用單例模式的應用程序運行時。所以一旦運行一次，我可以在整個項目中全局訪問連接。

use Illuminate\Cache\CacheManager; 
use Illuminate\Cache\MemcachedConnector; 
use Illuminate\Database\Capsule\Manager as Capsule; 
use INSP\Config; 
use INSP\Core; 
use INSP\Di; 

/** 
* Class ConnectionManager 
* 
* @package INSP\Database 
*/ 
class ConnectionManager 
{ 

    /** 
    * @var \Illuminate\Database\Connection 
    */ 
    protected static $instance; 

    /** 
    * Loads database configuration from static file if it exists if not it loads from 
    * Wordpress defaults 
    * 
    * @param bool $config 
    */ 
    public function __construct($config = false) 
    { 
     /* 
     * If config is not provided in the constructor check for a config file in the 
     * config directory, if that doesn't exist use the database config from wp_config 
     */ 
     if (!$config && file_exists(Core::baseDir() . '/Config/database.php')) { 
      $config = include(Core::baseDir() . '/Config/database.php'); 
     } else { 
      if (!defined('DB_HOST')) { 
       if (file_exists(Core::baseDir() . '/local-config.php')) { 
        define('WP_LOCAL_DEV', true); 
        require_once(Core::baseDir() . '/local-config.php'); 
       } else { 
        require_once(Core::baseDir() . '/production-config.php'); 

       } 
      } 
      $config = array(
       'driver' => 'mysql', 
       'host'  => DB_HOST, 
       'database' => DB_NAME, 
       'username' => DB_USER, 
       'password' => DB_PASSWORD, 
       'charset' => DB_CHARSET, 
       'collation' => 'utf8_unicode_ci', 
      ); 
     } 

     return self::connect($config); 

    } 

    /** 
    * This method is in charge or setting up all connection's including 
    * the k2 and mocked testing connection(uTest) 
    * 
    * @param $config 
    * 
    * @return \Illuminate\Database\Connection 
    */ 
    public static function connect($config) 
    { 
     $capsule = new Capsule(); 
     // Load some ancillary configurations 
     $k2Config = Config::getAll('Apis/k2'); 
     $unitConfig = array(
      'driver' => 'sqlite', 
      'database' => ':memory:', 
      'prefix' => '' 
     ); 
     // Add all needed configurations to connections and name them if needed 
     $capsule->addConnection($config); 
     $capsule->addConnection($k2Config, 'k2'); 
     $capsule->addConnection($unitConfig, 'uTest'); 

     // Add capsule to global namespace so we can use it later 
     $capsule->setAsGlobal(); 

     // Start the caching library so we can use the remember(ttl) method in our queries 
     $container = $capsule->getContainer(); 

     $cacheConfig = Config::getAll('cache'); 
     $memcachedServers = Config::get('cache.memcached'); 

     $container['memcached.connector'] = new MemcachedConnector(); 
     $container['config']['cache.driver'] = $cacheConfig['driver']; 
     $container['config']['cache.path'] = $cacheConfig['file']['directory']; 
     $container['config']['cache.connection'] = null; 
     $container['config']['cache.table'] = 'cache'; 
     $container['config']['cache.memcached'] = $memcachedServers; 
     $container['config']['cache.prefix'] = $cacheConfig['prefix']; 

     // If Memcached is not installed default to file storage 
     if (!class_exists('Memcached', false)) { 
      $container['config']['cache.driver'] = 'file'; 
     } 

     // Start Dependency Injection if it hasn't already been started 
     Di::init(); 
     $cacheManager = new CacheManager($container); 

     Di::set('cacheManager', $cacheManager); 

     $capsule->setCacheManager($cacheManager); 

     return $capsule->connection(); 
    } 

    /** 
    * @param bool $config 
    * 
    * @return ConnectionManager 
    */ 
    public static function init($config = false) 
    { 
     if (!is_object(self::$instance)) { 
      self::$instance = new ConnectionManager($config); 
     } 
     return self::$instance; 
    } 

} 

這是我的連接管理器，它使用框架外部的數據庫類。一旦這樣跑我還有一個門面即字面

use Illuminate\Database\Capsule\Manager; 

/** 
* Class DB 
* This is a Facade of the Connection established by ConnectionManager 
* 
* @package INSP\Database 
*/ 
class DB extends Manager 
    { 
    } 

，它可以讓我用DB::table() .......代替Manager::table()。

希望這會有幫助

Answer 2

你需要你建立連接的第一次，你需要它，並關閉連接，當應用程序被關閉（__destruct方法或register_shutdown）