_db = $this->getDbInstance();//Zend_Registry::get('mongoDB');     }         public function getDB() {
          return $this->_db;     }         public function find($query=array(),$sort = array("_id"=>1),$skip=0,$limit=10000) {
          return $this->_db->find($this->name, $query, $sort, $skip, $limit);     }         public function findOne($query) {
          return $this->_db->findOne($this->name, $query);     }         public function findAndModify($options) {
          return $this->_db->findAndModify($this->name, $options);     }         public function count($query) {
          return $this->_db->count($this->name, $query);     }         public function remove($query) {
          return $this->_db->remove($this->name, $query);     }         public function insert ($object) {
          return $this->_db->insert($this->name, $object);     }         public function update ($criteria, $object)     {
          return $this->_db->update($this->name, $criteria, $object);     }         public function aggregate(array $ops) {
          return $this->_db->aggregate($this->name, $ops);     }         public function getCondition($condition = null)     {
          $query= array();      if(!empty($condition)){
           foreach($condition as $k=>$v){
            if(!empty($v)){
             $query[$k] = trim($v);        }       }      }            return $query;     }         /**      * Load Smarty library      */     public static function LoadSmarty()     {
          require_once(SMARTY_DIR.'Smarty.class.php');      $smarty = new Smarty();      $smarty->template_dir = BASE_DIR.'templates/';      $smarty->compile_dir = BASE_DIR.'templates_c/';      $smarty->left_delimiter = "{
     {";      $smarty->right_delimiter = "}}";      $smarty->allow_php_tag=true;      return $smarty;     }         public static function LoadMySmarty()     {
          require_once(SMARTY_DIR.'MySmarty.php');      $mysmarty = new MySmarty();      $mysmarty->template_dir = BASE_DIR.'templates/';      $mysmarty->compile_dir = BASE_DIR.'templates_c/';      $mysmarty->left_delimiter = "{
     {";      $mysmarty->right_delimiter = "}}";      $mysmarty->allow_php_tag=true;      return $mysmarty;     }         public static  function LoadFront1126Smarty()     {
          require_once(SMARTY_DIR.'Front1126Smarty.php');      $mysmarty = new Front1126Smarty();      $mysmarty->template_dir = BASE_DIR.'templates/';      $mysmarty->compile_dir = BASE_DIR.'templates_c/';      $mysmarty->left_delimiter = "{
     {";      $mysmarty->right_delimiter = "}}";      $mysmarty->allow_php_tag=true;      return $mysmarty;     }         public static function LoadFrontSmarty()     {
          require_once(SMARTY_DIR.'FrontSmarty.php');      $fsmarty = new FrontSmarty();      $fsmarty->template_dir = BASE_DIR.'templates/';      $fsmarty->compile_dir = BASE_DIR.'templates_c/';      $fsmarty->left_delimiter = "{
     {";      $fsmarty->right_delimiter = "}}";      $fsmarty->allow_php_tag=true;      return $fsmarty;     } } //-------------------------------------------------------- class ConnectionFactory {
      　　private static $factory;  　　public static function getFactory()  　　{
       　　　　if(!self::$factory)   　　　　self::$factory =new ConnectionFactory(...);   　　　　return self::$factory; 　　 } 　　private $db; 　　public function getConnection() 　　{
     　　　　if(!$db)      　　$db =new PDO(...); 　　　　return $db; 　　} } //调用 function getSomething() {
         　　$conn =ConnectionFactory::getFactory()->getConnection();... //-----------------------------------------实例二------------------------------------------ class Database Singleton {
        // [Singleton]   private static $instance =null;   public static function getInstance()   {
          if(!self::$instance)     {
            self::$instance =new self();     }     return self::$instance;   }   privatefunction __clone(){}   // [/Singleton]   private $connection =null;   private function __construct()   {
          $this->connection = mysql_connect('localhost','root','admin');     if($this->connection)     {
            mysql_select_db('my_database');     }   }   //   // crud operations go here.   // } $db =DatabaseSingleton::getInstance(); $db->SomeCRUDOperation(); //----------------------------------实例三------------------------------------- class Database {
         private static $instance =null;   private static $conn;   private function __construct()   {
           self::$conn =new mysqli('localhost','root','root','database','3307');   }   public static function getInstance()   {
           if(self::$instance ==null){
             self::$instance =new Database();     }     return self::$instance;   }   public function query($sql)   {
           return self::$conn->query($sql);   } }