Django用mongoengine操作mongodb

无人驾驶 發表於 2019-9-13 09:58:00

最近在写Django项目，使用的是mongodb，虽然Django不支持NoSQL，但是mongoengine可以帮助我们像ORM一样在Django项目中去操作mongodb
推荐一个可视化工具  Robo 3T 
这里贴几个我觉得比较有帮助的帖子，特别是在一对一，一对多的引用
先放mongoengine的官方文档
http://docs.mongoengine.org/tutorial.html
这是翻译的中文文档，版本比较老，对应官方文档看 https://www.cnblogs.com/fillim/p/4864523.html
https://blog.csdn.net/qq_38890497/article/details/80392846
https://www.linuxzen.com/mongoengineshi-yong-bi-ji.html
1. 首先修改settings.py, 原来DATABASES完全不用去管它了, 全部设为空串就好, 然后在文件里加上下面的内容
如有必要可在INSTALLED_APPS中注册一下
<div class="cnblogs_code">
<pre>#settings.py

from mongoengine import connect
connect('DB_NAME')</pre>
</div>
#####ReferenceField 引用字段
<div class="cnblogs_code">
<pre>class Org(Document):
owner = ReferenceField('User')

class User(Document):
org = ReferenceField('Org', reverse_delete_rule=CASCADE)

User.register_delete_rule(Org, 'owner', DENY)</pre>
</div>
2.创建集合 
<div class="cnblogs_code">
<pre># model.py

from mongoengine import *
from datetime import datetime,timedeltaclass User(Document):
name = StringField(max_length=32) </pre>
<pre class="hljs python"><code>　　 age = IntField()
password = StringField(max_length=32</code></pre>
</div>
引用查询
<div class="cnblogs_code">
<pre>from mongoengine import *
from datetime import datetime,timedelta
from ReferencenField import *
import json
from bson import json_util

connect('mongotest')

# 一对一引用查询
author = User.objects.filter(name="John Smith")
author2 = Page.objects.filter(content="test3 Page").first().author

content = Page.objects.filter(author=a)
content_ = Page.objects(author__in=)

print(author.name)
print(author2.name)

print(content_)

for i in content:
print(i.author.name,':',i.content)

# 一对多引用查询
John_Smith = User.objects.filter(name="John Smith")
llz = User.objects.filter(name='lilinze')
# print(llz.name)

print('查询作者是llz的Page')
pages = Page.objects.filter(author=llz)
for i in pages :
print(i.content)

print('查询作者是John_Smith的Page')
pages = Page.objects.filter(author=John_Smith)
for i in pages:
print(i.content)</pre>
</div>
嵌入
<div class="cnblogs_code">
<pre>from mongoengine import *
from datetime import datetime,timedelta
from bson.objectid import ObjectId

connect('mongotest')

class User(Document):
name = StringField()
pages= StringField()
time = DateTimeField()

class Tags(EmbeddedDocument):
name = StringField()
date = DateTimeField(default=datetime.now())

class Page(Document):
content = StringField()
quadrant =StringField()
#两种嵌入写法
# tags = ListField(EmbeddedDocumentField('Tags'))
tags = EmbeddedDocumentListField('Tags')
author = ReferenceField(User,reverse_delete_rule = CASCADE)

user = User.objects.get(name='llz')
tag = Tags(name='123')
tag1 = Tags(name='456')
page = Page(content='嵌入1',quadrant='北面',tags=,author=user)
page.save()</pre>
</div>
Objectid转为字符串
<div class="cnblogs_code">
<pre>John = User.objects.filter(name="John Smith").id
print(John)
dict = {'John':John}
print('dict:',dict)
# j_son = json.dumps(dict)

print('--------ObjectId转为Json----------')
data = json_util.dumps(John)
print('data:',data)
print('type:',type(data))

print('--------Json--to--dict----------')
print('********************************')
dd = json.loads(data)
print(dd)
print(type(dd))
print(dd['$oid'])
print(type(dd['$oid']))
dd_ = {'$oid':dd['$oid']}
jdd_ = json.dumps(dd_)
objecdd_ = json_util.loads(jdd_)
print(objecdd_)
print(type(objecdd_))
print('********************************')

print('--------Json--to--ObjectId----------')
ObjectId = json_util.loads(data)
print(ObjectId)
print(type(ObjectId))</pre>
</div>
字符串转objectID
<div class="cnblogs_code">
<pre>from bson.objectid import ObjectId

a = '5bfe034c07aae823b440fdcf'

# 判断是否符合object格式

if ObjectId.is_valid(a):

A = ObjectId(a)

print(A)
# <class 'bson.objectid.ObjectId'>,id是bson

print(isinstance(A,ObjectId)) # True</pre>
</div>
create() ，存入一个新对象，并返回
<div class="cnblogs_code">
<pre>llzid = User.objects.create(name='zzz')
print(llzid.name)

>>>zzz</pre>
</div>
  
来源：https://www.cnblogs.com/yangyangming/p/11516121.html

頁: [1]

琼殿技术论坛's Archiver

Django用mongoengine操作mongodb