Mongoengine 简明教程
MongoEngine - Sorting
QuerySet 的 order_by() 函数用于按顺序获取查询结果。用法如下：
Qset.order_by(‘fieldname’)默认情况下，排序顺序为升序。对于降序，将 - 号附加到字段名称。例如，按升序获取价格列表：
from mongoengine import *
con=connect('newdb')
class products (Document):
ProductID=IntField(required=True)
company=StringField()
Name=StringField()
price=IntField()
for product in products.objects.order_by('price'):
print ("Name:{} company:{} price:{}".format(product.Name, product.company, product.price))Output
Name:Router company:Iball price:2000
Name:Scanner company:Cannon price:5000
Name:Printer company:Cannon price:12500
Name:Laptop company:Acer price:25000
Name:TV company:Philips price:31000
Name:Laptop company:Dell price:45000
Name:TV company:Samsung price:50000以下代码将按 name 降序获取列表：
for product in products.objects.order_by('-Name'):
print ("Name:{} company:{} price:{}".format(product.Name, product.company, product.price))Output
Name:TV company:Samsung price:50000
Name:TV company:Philips price:31000
Name:Scanner company:Cannon price:5000
Name:Router company:Iball price:2000
Name:Printer company:Cannon price:12500
Name:Laptop company:Acer price:25000
Name:Laptop company:Dell price:45000您还可以在多个字段上进行排序。此代码将按升序获取按公司、价格列表。
for product in products.objects.order_by('company','price'):
print ("Name:{} company:{} price:{}".format(product.Name, product.company, product.price))