mongoengine使用示例

#!/usr/bin/env python
# -*- coding: utf-8 -*-
'''
Created on 2017年10月19日
@author: zzy
'''
from mongoengine import *

#连接数据库
def lazy_connect():
    #mongodb://dbuser:sa123@192.168.1.58:27017/db_datacn
    connect('db_datacn', host='mongodb://192.168.1.58/', username='dbuser', password='sa123')

lazy_connect()

# Defining our documents
# 定义文档user,post,对应集合user,post
class User(Document):
    email = StringField(required=True)
    first_name = StringField(max_length=50)
    last_name = StringField(max_length=50)

#Embedded documents 嵌入的文件,it doesn’t have its own collection in the database
class Comment(EmbeddedDocument):
    content = StringField()
    name = StringField(max_length=120)
    
class Post(Document):
    title = StringField(max_length=120, required=True)
    # ReferenceField相当于foreign key
    author = ReferenceField(User, reverse_delete_rule=CASCADE)
    tags = ListField(StringField(max_length=30))
    comments = ListField(EmbeddedDocumentField(Comment))
    #允许继承
    meta = {'allow_inheritance': True}

#Post的子类
class TextPost(Post):
    content = StringField()

#Post的子类
class ImagePost(Post):
    image_path = StringField()

#Post的子类
class LinkPost(Post):
    link_url = StringField()
    
def save_user():
#     john = User(email='john@example.com')
#     john.first_name = 'john'
#     john.last_name = 'cvsh'
#     john.save()
#     
#     ross = User(email='ross@example.com')
#     ross.first_name = 'Ross'
#     ross.last_name = 'Lawley'
#     ross.save()
#     
#     post1 = TextPost(title='Fun with MongoEngine', author=john)
#     post1.content = 'Took a look at MongoEngine today, looks pretty cool.'
#     post1.tags = ['mongodb', 'mongoengine']
#     post1.save()
# 
#     post2 = LinkPost(title='MongoEngine Documentation', author=ross)
#     post2.link_url = 'http://docs.mongoengine.com/'
#     post2.tags = ['mongoengine']
#     post2.save()

#     for post in Post.objects:
#         print(post.title)
#         
#     for post in TextPost.objects:
#         print(post.content)
#         
#     for post in Post.objects:
#         print(post.title)
#         print('=' * len(post.title))
#         if isinstance(post, TextPost):
#             print(post.content)
#         if isinstance(post, LinkPost):
#             print('Link: {}'.format(post.link_url))
    Post.objects(tags='mongoengine').update(tags=['abc','20171019'])  
    for post in Post.objects.all():      
    #for post in Post.objects(tags='mongoengine'):
        print(post.title)
    #Post.objects(tags='mongodb').delete()   
    
    num_posts = Post.objects(tags='mongodb').count()
    print('Found {} posts with tag "mongodb"'.format(num_posts))

if __name__ == '__main__':
    save_user()