Question

我不确定为什么这会导致我这样的问题，但我似乎无法弄明白。我的Mezzanine / Cartridge产品数据库中的产品有CSV和PDF导出。它会连续导出每个ProductVariation。工作得很好，但我需要添加一个过滤器，例如只导出已发布的产品。 ProductVariations与产品型号具有外键关系：

class ProductVariation(Priced):
"""
A combination of selected options from
``SHOP_OPTION_TYPE_CHOICES`` for a ``Product`` instance.
"""

product = models.ForeignKey("Product", related_name="variations")

产品型号子类可显示：

class Product(Displayable, Priced, RichText, AdminThumbMixin):
"""
Container model for a product that stores information common to
all of its variations such as the product's title and description.
"""

Displayable类用于确定是否仅为普通用户或员工显示产品：

CONTENT_STATUS_DRAFT = 1
CONTENT_STATUS_PUBLISHED = 2
CONTENT_STATUS_COMPLETE = 3
CONTENT_STATUS_INACTIVE = 4

CONTENT_STATUS_CHOICES = (
    (CONTENT_STATUS_DRAFT, _("Draft")),
    (CONTENT_STATUS_PUBLISHED, _("Online")),
    (CONTENT_STATUS_COMPLETE, _("Complete")),
    (CONTENT_STATUS_INACTIVE, _("Inactive")),
)


class Displayable(Slugged, MetaData, TimeStamped):
"""
Abstract model that provides features of a visible page on the
website such as publishing fields. Basis of Mezzanine pages,
blog posts, and Cartridge products.
"""

status = models.IntegerField(_("Status"),
    choices=CONTENT_STATUS_CHOICES, default=CONTENT_STATUS_DRAFT,
    help_text=_("The General public can only view content that has ONLINE status."))

在尝试按状态过滤结果时，我似乎无法按照预期的方式使其工作。在我的报告视图中，我将添加以下内容：

product_variations = ProductVariation.objects.filter('product__status' == 'CONTENT_STATUS_PUBLISHED')

但它只是给了我一个“'bool'对象不可迭代”的错误。我做错了什么？

Answer 1

当你写：

ProductVariation.objects.filter('product__status' == 'CONTENT_STATUS_PUBLISHED')

表达式'product__status' == 'CONTENT_STATUS_PUBLISHED'变为布尔值。

正确的语法是：

ProductVariation.objects.filter(product__status = 'CONTENT_STATUS_PUBLISHED')

通过父类的布尔字段过滤queryset

1 个答案: