python - 丢弃 Django 查询集中的旧元素

Question

我的数据库中有一个元素列表，每个元素都有自己的日期时间字段。我想丢弃比今天更旧的元素，这意味着我只会看到 future 的元素。

这是我当前的代码:

def get_dates_approved(request):
    user = request.user
    alreadyRated = [x.date.id for x in Ratings.objects.filter(rator=user)]
    dates = Dating.objects.filter((Q(creator=user) | Q(assignee=user)) & Q(accepted=True)) \
                      .exclude(id__in=alreadyRated)
    return dates

定义日期的字段是这个:

finalDate = models.DateTimeField(default=datetime.now)

Answer 1

Django 查询集具有字段查找功能。

来自 Django 文档，

Field lookups are how you specify the meat of an SQL WHERE clause. They’re specified as keyword arguments to the QuerySet methods filter(), exclude() and get().

有许多内置查找可用，例如 exact、iexact、contains、gt 、gte、lt、lte 等等。更多信息请引用Django queryset field lookups .

回答你的问题

dates = Dating.objects.filter((Q(creator=user) | Q(assignee=user)) & Q(accepted=True)) \
                  .exclude(id__in=alreadyRated)

应该是

dates = Dating.objects.filter((Q(creator=user) | Q(assignee=user)) & Q(accepted=True)) \
                  .exclude(id__in=alreadyRated, finalDate__lt=datetime.today())

所以你的函数应该看起来像

from datetime import datetime

def get_dates_approved(request):
    user = request.user
    alreadyRated = [x.date.id for x in Ratings.objects.filter(rator=user)]
    dates = Dating.objects.filter((Q(creator=user) | Q(assignee=user)) & Q(accepted=True)) \
                      .exclude(id__in=alreadyRated, finalDate__lt=datetime.today())