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python - 不支持为 CharField 查找“xx”或不允许在该字段上加入

问题描述

我正在尝试使用 AJAX GET 请求获取用户创建的列表。但是，我的过滤返回了这个问题：

Unsupported lookup 'user' for CharField or join on the field not permitted.

我不确定这里出了什么问题。

这是我的模型：

class UserList(models.Model):
    list_name = models.CharField(max_length=255)
    user = models.ForeignKey(User, on_delete=models.CASCADE) #is this okay?

    def __str__(self):
        return self.list_name

class UserVenue(models.Model):
    venue = models.ForeignKey(mapCafes, on_delete=models.PROTECT)
    list = models.ForeignKey(UserList, on_delete=models.PROTECT)

    class Meta:
        unique_together = ['list','venue']

这是views.py：

# dashboard
def get_userlists(request):
    template_name = '/testingland/dashboard/'
    username = None
    if request.user.is_authenticated:
        username = request.user.username
        print(username)
    list = request.GET.get('userlist', None)
    qs = UserList.objects.filter(list_name__user=username)
    return qs

FWIW 这里是 ajax 调用：

const showUserLists = function(){
  document.getElementById("userLists")
    console.log('The Space Exists')
    $.ajax({
        type: 'GET',
        url: '/electra/get_userlists/',
        data: {
        },
        success: function (data) {
            console.log(data); 
          }
        });
};

追溯：

Traceback (most recent call last):
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/core/handlers/base.py", line 179, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/Users//Desktop/Coding/anybody/anybody1/testingland/views.py", line 117, in get_userlists
    qs = UserList.objects.filter(list_name__user=username)
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/db/models/query.py", line 942, in filter
    return self._filter_or_exclude(False, *args, **kwargs)
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/db/models/query.py", line 962, in _filter_or_exclude
    clone._filter_or_exclude_inplace(negate, *args, **kwargs)
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/db/models/query.py", line 969, in _filter_or_exclude_inplace
    self._query.add_q(Q(*args, **kwargs))
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1358, in add_q
    clause, _ = self._add_q(q_object, self.used_aliases)
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1380, in _add_q
    split_subq=split_subq, check_filterable=check_filterable,
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1319, in build_filter
    condition = self.build_lookup(lookups, col, value)
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1159, in build_lookup
    lhs = self.try_transform(lhs, lookup_name)
  File "/Users//Desktop/Coding/anybody/avenv/lib/python3.6/site-packages/django/db/models/sql/query.py", line 1200, in try_transform
    "permitted%s" % (name, output_field.__name__, suggestion)
django.core.exceptions.FieldError: Unsupported lookup 'user' for CharField or join on the field not permitted.

标签： pythondjango

解决方案

您正在过滤 a UserList，因此list_namea 的 aUserList是 a CharField，因此使用list_name__user没有意义。你过滤：

qs = UserList.objects.filter(user=request.user)

获得UserList给定的所有 s user。

注意：通常使用settings.AUTH_USER_MODEL[Django-doc]引用用户模型比直接使用User模型 [Django-doc]更好。有关更多信息，您可以查看文档的引用User模型部分。

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