How do I make tables using one of models field as headers

Using Django Templates & Frontend
1

Hello!

I got a question how do I make tables using one of models field as headers, let me explain:

My models (please, don’t mind native language):

class Timeperiod(models.Model):
    '''Периоды.'''
    start_date = models.DateField('дата начала')
    end_date = models.DateField('дата окончания')
    target_duration = models.DurationField('длительность')
    is_open = models.BooleanField('открыт', default=False)

    class Meta:
        verbose_name = 'период'
        verbose_name_plural = 'периоды'

    @property
    def test(self) -> str:
        return 'test'

    @property
    def days(self) -> list:
        delta = self.end_date - self.start_date
        ds = []
        for i in range(delta.days + 1):
            ds.append(self.start_date + timedelta(days=i))
        return ds

    def __str__(self) -> str:
        return ' - '.join([str(self.start_date), str(self.end_date), str(self.target_duration), str(self.days)])

class Timetracking(models.Model):
    '''Списания времени.'''
    employee = models.ForeignKey(Employee, on_delete=models.PROTECT, verbose_name='сотрудник')
    project = models.ForeignKey(Project, on_delete=models.PROTECT, verbose_name='проект')
    timeperiod = models.ForeignKey(Timeperiod, on_delete=models.PROTECT, verbose_name='период')
    date = models.DateField('дата')
    time = models.DurationField('трудозатраты')

    class Meta:
        verbose_name = 'списание'
        verbose_name_plural = 'списания'

    def __str__(self) -> str:
        return f'{self.employee} - {self.project}: {self.date} {self.time}'

I want to have data displayed like this:
Timeperiod.days[1] | … Timeperiod.days[n]
sum(all_timetrackings_at_that_day) | sum(all_timetrackings_at_that_day)
…

But I just have now idea where to start to get data like this

2

Are you talking about creating an html table this way?

If so, you can iterate over that list using the template for tag.

3

something like this as a starting point (assuming i’ve understood the models … :p)?

time_periods = TimePeriod.objects.filter(...).annotate(
    timetracking_time_sum=Subquery(
        Timetracking.objects.filter(
            timeperiod__pk=OuterRef('pk'),
        ).values('timeperiod__pk').order_by('timeperiod__pk').annotate(
            total=Sum('time')
        ).values_list(
            'total'
        )[:1]
        output_field=models.DurationField(),
        default=Value(0)
    )
)

and then as Ken says, simple loop.

4

Thank you gentlemen, that was exactly what I needed!