django-JSONField的不支持查找或不允许在字段上加入

问题描述

我的模型中的Json字段为-

I am having a Json field in my models as -

class Product(models.Model):
    ...
    detailed_stock           = JSONField(load_kwargs={'object_pairs_hook': collections.OrderedDict},default=dict)

我的数据库中有值-

{
  "total":0,
  "5[1]":0
}

我正在尝试过滤总计为0的对象，因为我尝试过-

I am trying to filter objects with total = 0, for that I tried -

Product.objects.filter(detailed_stock__total = 0)但会引发错误-

不支持对JSONField的查找总计"或不允许在字段上进行联接.

按照 documentation 允许以下代码.

这是完整的追溯-

Traceback (most recent call last):
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\core\handlers\exception.py", line 35, in inner
    response = get_response(request)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\core\handlers\base.py", line 128, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\core\handlers\base.py", line 126, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\views\generic\base.py", line 69, in view
    return self.dispatch(request, *args, **kwargs)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\braces\views\_access.py", line 102, in dispatch
    request, *args, **kwargs)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\views\generic\base.py", line 89, in dispatch
    return handler(request, *args, **kwargs)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\views\generic\list.py", line 142, in get
    self.object_list = self.get_queryset()
  File "c:\Users\lenovo\Desktop\My_Django_Stuff\bekaim\accounts\views.py", line 142, in get_queryset
    queryset = Product.objects.filter(detailed_stock__total = 0)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\db\models\query.py", line 836, in filter
    return self._filter_or_exclude(False, *args, **kwargs)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\db\models\query.py", line 854, in _filter_or_exclude
    clone.query.add_q(Q(*args, **kwargs))
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\db\models\sql\query.py", line 1253, in add_q
    clause, _ = self._add_q(q_object, self.used_aliases)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\db\models\sql\query.py", line 1271, in _add_q
    current_negated, allow_joins, split_subq)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\db\models\sql\query.py", line 1277, in _add_q
    split_subq=split_subq,
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\db\models\sql\query.py", line 1215, in build_filter
    condition = self.build_lookup(lookups, col, value)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\db\models\sql\query.py", line 1069, in build_lookup
    lhs = self.try_transform(lhs, name)
  File "C:\Users\lenovo\AppData\Local\conda\conda\envs\myDjangoEnv\lib\site-packages\django\db\models\sql\query.py", line 1115, in try_transform
    (name, lhs.output_field.__class__.__name__))
django.core.exceptions.FieldError: Unsupported lookup 'total' for JSONField or join on the field not permitted.
[31/Dec/2018 16:13:37] "GET /accounts/product-list/?clean=outofstock HTTP/1.1" 500 150927

我在互联网上进行了搜索，但找不到解决方案，请提供帮助.

I searched on internet but unable to find the solution, please help.

推荐答案

我认为您正在使用 django-jsonfield，如 load_kwargs = {'object_pairs_hook':collections.OrderedDict} 所示，而不是 django.contrib.postgres.fields.JSONField .

I think you are using django-jsonfield as indicated by load_kwargs={'object_pairs_hook': collections.OrderedDict} instead of django.contrib.postgres.fields.JSONField.

django-jsonfield 适用于不提供本机 dict 类型且基于简单 TextField .当您使用 product.detail_stock 访问字段值时，内部保存的 str 将使用 json.loads() .因此，您只能使用包含和包含之类的操作来查询该字段.

django-jsonfield is for databases which don't offer a native dict type and is based on a simple TextField. When you access the field value using product.detail_stock the internally saved str is converted to dict using json.loads() by the field itself. Hence you can only use operations like icontains and contains for querying that field.

如果将postgres用作数据库，则可以按照文档说明充分利用 django.contrib.postgres.fields.JSONField .但是您必须使用 django.contrib.postgres.fields import JSONField 导入正确的 JSONfield .

If you are using postgres as a database, you are able to take full advantage of django.contrib.postgres.fields.JSONField as the documentation states. But you have to import the correct JSONfield by using django.contrib.postgres.fields import JSONField.

对于 mysql (软件包 django-mysql ).

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