public function ultimosGrupos($limite){
    try {
        $query = "SELECT * FROM groups ORDER BY id ASC LIMIT :limite";
        $this->Select = $this->Conn->prepare($query);
        $this->Select->bindParam(':limite' , $limite, PDO::PARAM_INT);
        $this->Select->execute();
        if($this->Select->rowCount() > 0){
            return $this->Select->fetchAll(PDO::FETCH_ASSOC);
        }else{
            return FALSE;
        }
    } catch (PDOException $exc) {
        exibeMensagens("Erro ao consultar. {$exc->getMessage()}", WS_ERROR);
    }
}