有我的问题，我有下一个申请：
class Product(models.Model):
CHOICES = ('VM', 'BM')
name = models.CharField(max_length=64, unique=True)
types = models.CharField(choices=CHOICES, max_length=16,
default=CHOICES[0])
和
from products import Product
class Invent(models.Model):
item = models.ForeignKey(Product, to_field='name', default=1)
我也为他们创建了API。它工作正常但我需要按模型创建过滤器并且不知道如何。 例如，我需要在API中获取所有项目列表，但仅在产品应用程序中它是＆＃34; VM＆＃34;。我怎么能这样做？
如果需要，有一些示例，但它不是过滤： EX：
class ShellMessageFilterVM(django_filters.FilterSet):
types = Product.objects.filter(types="VM")
item = django_filters.ModelChoiceFilter(queryset=Invent.objects.filter(item=types))
class Meta:
model = Invent
fields = ['item']
class InventoryAvailableVMList(ListAPIView):
serializer_class = InventSerializer
queryset = Invent.objects.all()
filter_class = ShellMessageFilterVM
收到错误：
（1242，＆＃39;子查询返回超过1行＆＃39;）
完整追溯：
Environment:
Request Method: GET
Django Version: 1.9 Python Version: 2.7.5 Installed Applications: ['product.apps.ProductConfig', 'invent.apps.InventConfig',, 'django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.messages', 'django.contrib.staticfiles', 'rest_framework', 'rest_framework.authtoken'] Installed Middleware: ['django.middleware.security.SecurityMiddleware', 'django.contrib.sessions.middleware.SessionMiddleware', 'django.middleware.common.CommonMiddleware', 'django.middleware.csrf.CsrfViewMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'django.contrib.auth.middleware.SessionAuthenticationMiddleware', 'django.contrib.messages.middleware.MessageMiddleware', 'django.middleware.clickjacking.XFrameOptionsMiddleware']
Template error: In template /usr/local/hosting/hosting/lib/python2.7/site-packages/rest_framework/templates/rest_framework/filters/django_filter.html, error at line 4 1242 1 : {% load i18n %} 2 : <h2>{% trans "Field filters" %}</h2> 3 : <form class="form" action="" method="get"> 4 : {{ filter.form.as_p }} 5 : <button type="submit" class="btn btn-primary">{% trans "Submit" %}</button> 6 : </form> 7 :
Traceback:
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
174. response = self.process_exception_by_middleware(e, request)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
172. response = response.render()
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/template/response.py" in render
160. self.content = self.rendered_content
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/rest_framework/response.py" in rendered_content
71. ret = renderer.render(self.data, media_type, context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/rest_framework/renderers.py" in render
675. context = self.get_context(data, accepted_media_type, renderer_context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/rest_framework/renderers.py" in get_context
654. 'filter_form': self.get_filter_form(data, view, request),
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/rest_framework/renderers.py" in get_filter_form
596. html = backend().to_html(request, queryset, view)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/rest_framework_filters/backends.py" in to_html
35. return compat.template_render(template, context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/rest_framework/compat.py" in template_render
232. return template.render(context, request=request)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/template/backends/django.py" in render
95. return self.template.render(context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/template/base.py" in render
206. return self._render(context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/template/base.py" in _render
197. return self.nodelist.render(context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/template/base.py" in render
988. bit = node.render_annotated(context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/template/base.py" in render_annotated
955. return self.render(context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/template/base.py" in render
1039. output = self.filter_expression.resolve(context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/template/base.py" in resolve
705. obj = self.var.resolve(context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/template/base.py" in resolve
846. value = self._resolve_lookup(context)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/template/base.py" in _resolve_lookup
909. current = current()
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/forms/forms.py" in as_p
281. errors_on_separate_row=True)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/forms/forms.py" in _html_output
218. 'field': six.text_type(bf),
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/utils/html.py" in <lambda>
381. klass.__unicode__ = lambda self: mark_safe(klass_unicode(self))
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/forms/boundfield.py" in __str__
43. return self.as_widget()
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/forms/boundfield.py" in as_widget
101. return force_text(widget.render(name, self.value(), attrs=attrs))
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/forms/widgets.py" in render
528. options = self.render_options(choices, [value])
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/forms/widgets.py" in render_options
554. for option_value, option_label in chain(self.choices, choices):
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/forms/models.py" in __iter__
1109. for obj in queryset:
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/db/models/query.py" in __iter__
52. results = compiler.execute_sql()
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/db/models/sql/compiler.py" in execute_sql
852. cursor.execute(sql, params)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/db/backends/utils.py" in execute
79. return super(CursorDebugWrapper, self).execute(sql, params)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/db/backends/utils.py" in execute
64. return self.cursor.execute(sql, params)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/db/utils.py" in __exit__
95. six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/db/backends/utils.py" in execute
64. return self.cursor.execute(sql, params)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/django/db/backends/mysql/base.py" in execute
112. return self.cursor.execute(query, args)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/MySQLdb/cursors.py" in execute
205. self.errorhandler(self, exc, value)
File "/usr/local/hosting/hosting/lib/python2.7/site-packages/MySQLdb/connections.py" in defaulterrorhandler
36. raise errorclass, errorvalue
Exception Type: OperationalError at /fulfillment/api/inventory_available/vm/ Exception Value: (1242, 'Subquery returns more than 1 row')
我的serializers.py
class InventSerializer(serializers.ModelSerializer):
item = serializers.SlugRelatedField(queryset=Product.objects.all(),
slug_field='name')
class Meta:
model = Invent
fields = ('id', 'item')
答案 0 :(得分：1)
你应该看一下documentation about FilterSet。
如果您想按item.types进行过滤，则ShellMessageFilterVM应如下所示：
class ShellMessageFilterVM(filters.FilterSet):
class Meta:
model = Item
fields = ['item__types']
然后您可以使用?item__types=VM