postgresql Django查询集过滤器文件字段不为空
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Django queryset filter filefield not empty
提问by Spoutnik16
I'm trying to filter a queryset, to exclude the one with no file. And I can't get it work, except by numberless iterations.
我正在尝试过滤查询集，以排除没有文件的查询集。我不能让它工作，除非无数次迭代。
class Something(models.Model):
name = models.CharField(max_length=512)
file = models.FieldField(upload_to="files", null=True, blank=True)
then, to get the one with a file
然后，得到一个文件
# this give me all objects
Something.objects.exclude(file__exact='')
# this is a valid solution, but hell, something easier should exist,
something_with_files = set()
for s in Something.objects.all():
if s.file:
something_with_files.add(s)
What is the real solution to this ?
什么是真正的解决方案？
PS: working on PostGres, dunno if that can change anything at that point.
PS：在 PostGres 上工作，不知道这是否可以改变当时的任何东西。
回答by Eugene Soldatov
Exact is unnecessary here:
这里不需要精确：
Something.objects.exclude(file='')
回答by simP
There are better options, I think:
有更好的选择，我认为：
from django.db.models import Q
Something.objects.filter(~Q(file__isnull=True))
or
或者
Something.objects.exclude(file__isnull=True)
回答by daaawx
This worked perfectly for me:
这对我来说非常有效：
objects = MyModel.objects.exclude(
Q(file='')|Q(file=None)
)
https://books.agiliq.com/projects/django-orm-cookbook/en/latest/filefield.html
https://books.agiliq.com/projects/django-orm-cookbook/en/latest/filefield.html
回答by Daniel Roseman
Your field allows nulls, so I guess the ones without files have the field as null, not the empty string. Try this:
你的字段允许空值，所以我猜那些没有文件的字段为空，而不是空字符串。试试这个：
Something.objects.exclude(file=None)
