这是我的 Database.php . 当我进入我的网站时，它会显示一个
1040 too many connection Pdo 例外。

class Database extends \PDO
{

    public function __construct($dsn, $usr = null, $pwd = null, array $options = array())
    {
        $options = $options + $this->getDefaultOptions();
        @parent::__construct($dsn, $usr, $pwd, $options);
    }

    protected function getDefaultOptions()
    {
        return array(
            \PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION,
            \PDO::ATTR_DEFAULT_FETCH_MODE => \PDO::FETCH_ASSOC,
            \PDO::ATTR_EMULATE_PREPARES => false,
            \PDO::ATTR_STATEMENT_CLASS => array('Slim\\PDO\\Statement', array($this)),
            );
    }

   /**
    * @param array $columns
    *
    * @return SelectStatement
    */
    public function select(array $columns = array('*'))
    {
        return new SelectStatement($this, $columns);
    }

   /**
    * @param array $columnsOrPairs
    *
    * @return InsertStatement
    */
    public function insert(array $columnsOrPairs = array())
    {
        return new InsertStatement($this, $columnsOrPairs);
    }

   /**
    * @param array $pairs
    *
    * @return UpdateStatement
    */
    public function update(array $pairs = array())
    {
        return new UpdateStatement($this, $pairs);
    }

   /**
    * @param null $table
    *
    * @return DeleteStatement
    */
    public function delete($table = null)
    {
        return new DeleteStatement($this, $table);
    }
}
mysqli_close();