如何通过自引用ManyToManyField获取与零件关联的所有项目?如何修复我的观点以使 part_list 包含与'product'关联的所有部分的列表以及order_by指定的顺序?
# views.py
def productdetail(request, slug):
product = get_object_or_404(PartModel, slug=slug)
part_list = PartModel.objects.all().filter(buildpart__id=product.pk).order_by('family__type')
return render(request, 'productdetail.html', locals())
这是模板:
# productdetail.html
<header>
<h1>'{{ product.name }}' Detail Page</h1>
</header>
<p>{{ product.name }}
<p>{{ product.slug }}
<p>{{ product.family }}
<p>{{ product.family.type }}
<p>{{ product.family.make }}
<p>${{ product.price }}
{% for part in part_items %}
<p>{{ part.name }}
{% endfor %}
注意PartModel模型通过buildpart字段保存我们的库存及其自引用的BuildPart ManyToMany模型:
class PartModel(models.Model):
family = models.ForeignKey(PartFamily)
name = models.CharField("Model Name", max_length=50, unique=True)
buildpart = models.ManyToManyField('self', through='BuildPart',
symmetrical=False, related_name='+')
class Build(models.Model):
build = models.ForeignKey(PartModel, related_name='+')
part = models.ForeignKey(PartModel, related_name='+')
quantity = models.PositiveSmallIntegerField(default=1)
class Meta:
abstract = True
unique_together = ('build', 'part')
def __unicode__(self):
return self.build.name + ' with ' + str(self.quantity) + ' * ' + \
self.part.family.make.name + ' ' + self.part.name
class BuildPart(Build):
pass
class Meta:
verbose_name = "Build Part"
为了使用order_by子句以正确的顺序获取所有内容,我们按照'family'字段访问PartFamily模型:
class PartFamily(models.Model):
make = models.ForeignKey(PartMake)
type = models.ForeignKey(PartType)
name = models.CharField("Family Name", max_length=30,
unique=True)
slug = models.SlugField(unique=True)
最后,我们使用'order'字段进入模型,我们希望按相关项排序,PartType:
class PartType(models.Model):
name = models.CharField("Part Type", max_length=30, unique=True)
slug = models.SlugField(unique=True)
order = models.PositiveSmallIntegerField()
description = models.TextField(blank=True, null=True)
答案 0 :(得分:0)
在罗斯曼的帮助下,我能够找到自己问题的答案。 part_list 行应如下所示:
# views.py
part_list = product.buildpart.all().order_by('family__type')
一旦Roseman指出变量名称不匹配,我就使用QuerySet,因为它对我来说最有意义,而且它有效!