Django中F函数的使用示例代码详解

post = Post.objects.get(...)
post.views += 1
post.save()

from django.db.models import F

post = Post.objects.get(...)
post.views = F('views') + 1
post.save()

...
post.save()
# 重新取值
post = Post.objects.get(...)

...
post.save()
# 重新取值
post.refresh_from_db()

# models.py
class Age(models.Model):
  year = models.IntegerField(default=6)
  month = models.IntegerField(default=10)

# --------------

# 获取所有 year > month 的数据
res = Age.objects.filter(year__gt=F('month'))

Age.objects.filter(year__gt=F('month') * 2)
Age.objects.filter(year__gt=F('month') + F('year'))

> from datetime import timedelta
> Entry.objects.filter(date__gt=F('pub_date') + timedelta(days=3))

# models.py
class Person(...):
  name = ...

class People(...):
  name = ...

class Age(...):
  ...
  person = models.OneToOneField(Person, ...)
  people = models.OneToOneField(People, ...)

# --------------

# 获取所有 person.name == user.name 的数据
res = Age.objects.filter(person__name=F('people__name'))