Question

我在Django模型中有两个TimeField，我想在另一个数据库字段，函数或类或任何最佳实践中计算持续时间。

我以后想使用此信息来显示按“ prosjekt”和“ aktivitet”排序的信息。例如：

Prosjekt1
aktivitet1 = 4 hours
aktivitet2 = 2,5 hours
aktivitet3 = 1 hour
Prosjekt2
aktivitet1 = 5,5 hours
aktivitet3 = 0,5 hours
Prosjekt3
aktivitet3 = 8,5 hours
etc.

这是我的模特

from django.db import models
from django.contrib.auth.models import User
from prosjektregister.models import Prosjekt

class Aktivitet(models.Model):
    aktivitet = models.CharField(max_length=100)

    def __str__(self):
        return self.aktivitet

class Tid(models.Model):
    author = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, blank=True)
    prosjekt = models.ForeignKey(Prosjekt, on_delete=models.CASCADE)
    dato = models.DateField()
    tid_fra = models.TimeField()
    tid_til = models.TimeField()
    aktivitet = models.ForeignKey(Aktivitet, on_delete=models.SET_NULL, null=True)

    def publish(self):
        self.save()

我的观点：

@login_required
def reg_tid(request):
    if request.method == 'POST':
        form = TidForm(request.POST, user=request.user)
        if form.is_valid():
            form.save()
            return HttpResponseRedirect('/tid/tidsregister/')
    else:
        form = TidForm(user=request.user)

    return render(request, 'tid/tid.html', {'form': form})


@method_decorator(login_required, name='dispatch')
class TidsRegister(ListView):
    model = Tid
    template_name = 'tid/tidsregister.html'
    context_object_name = 'tidsregister'

    def get_queryset(self):
        return Tid.objects.filter(author=self.request.user)


@login_required
def tid_edit(request, pk):
    post = get_object_or_404(Tid, pk=pk)
    if request.method == 'POST':
        form = TidForm(request.POST, instance=post, user=request.user)
        if form.is_valid():
            post = form.save()

            return HttpResponseRedirect('/tid/tidsregister/')

    else:
        form = TidForm(instance=post, user=request.user)

    return render(request, 'tid/tid.html', {'form': form})

Answer 1

我将尝试提供完整的示例，我想您可以从这里找出答案：

class Activity(models.Model):
    title = models.CharField(
        max_length=255,
        verbose_name="Title",
    )

    def __str__(self):
        return self.title

class Period(models.Model):
    activity = models.ForeignKey(
        to=Activity,
        on_delete=models.CASCADE,
        related_name="periods"
        verbose_name="Activity",
    )
    title = models.CharField(
        max_length=255,
        verbose_name="Title",
    )
    start_at = models.DateTimeField(
        verbose_name="Start at",
    )
    end_at = models.DateTimeField(
        verbose_name="End at",
    )

    def __str__(self):
        return "Period"

activities = Activity.objects.all()

for activity in Activity.objects.all():
    print(f"Activity: {activity.title}")

    print("Periods:")

    for period in activity.periods.all():
        print(f"{period.title} - {period.end_at - period.start_at}")  # (period.end_at - period.start_at) is a timedelta object, you can get (period.end_at - period.start_at).total_seconds() for example

django计算两个时域之间的持续时间

1 个答案: