<?php
class DB_MySQL {
  // ...

  public function connect($host, $database, $user, $pass) {
    $this->connection = @mysql_connect(
      $host,
      $user,
      $pass,
      TRUE
    );

    if (!$this->connection) {
      throw new DB_Exception(
        'Konnte keine Verbindung zur Datenbank aufbauen.',
        @mysql_errno()
      );
    }

    if (!@mysql_select_db($database, $this->connection)) {
      throw new DB_Exception(
        'Konnte die gewünschte Datenbank nicht auswählen.',
        @mysql_errno($this->connection)
      );
    }
  }

  // ...

  public function query($query) {
    if (is_resource($this->connection)) {
      if (is_resource($this->result)) {
        @mysql_free_result($this->result);
      }

      $this->result = @mysql_query(
        $query,
        $this->connection
      );

      if (!$this->result) {
        throw new DB_Exception(
          @mysql_error($this->connection),
          @mysql_errno($this->connection)
        );
      }
    }
  }

  // ...
}
?>