Hello, guys!
I have a simple code, which not correct work
He throw error if i try sort items by @hybrid_property
*My version of entity class:*
class Product(Base) :
__tablename__ = 'products'
Id = Column('id', Integer, primary_key=True, autoincrement=True)
TitleTranslit = Column('title_translit', String)
Title = Column('title', String)
Description = Column('description', String)
CurrentPrice = Column('current_price', Integer)
OldPrice = Column('old_price', Integer)
CategoryId = Column('category_id', Integer, ForeignKey('categories.id'))
Characteristics:List[ProductCharacteristic] =
relationship('ProductCharacteristic',
primaryjoin="and_(ProductCharacteristic.ProductId==Product.Id)",
lazy='joined')
Reviews:List[ProductReview] = relationship('ProductReview',
primaryjoin="and_(ProductReview.ProductId==Product.Id)", lazy='joined')
Images:List[ProductImage] = relationship('ProductImage',
primaryjoin="and_(ProductImage.ProductId==Product.Id)", lazy='joined')
NumberOfViews = Column('number_of_views', Integer)
@hybrid_property
def Rating(self) :
result = 0
reviewsCount = len(self.Reviews)
if (reviewsCount > 0) :
for review in self.Reviews :
result += review.Rating
result = result / reviewsCount
return result
*My version of call sort event by @hybrid_property:*
filteredProductsQuery = self._sessionService.DBContext.query(Product)\
.filter(Product.CategoryId.in_(categoriesIds)).outerjoin(Product.Characteristics)
if sortType == SortType.HighestRate.value :
filteredProductsQuery =
filteredProductsQuery.order_by(Product.Rating.desc())
*Throwed error if i try execute this query:*
TypeError: object of type 'InstrumentedAttribute' has no len()
--
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