Python中mongodb使用

Posted 2020-10-05

MongoDB的层级为 database -->collection --> document

安装MongoDB，启动mongo服务

安装Python的mongo模块

pip install pymongo

安装完后查看

pip list

模块引用

import pymongo

建立连接

import pymongo
from pymongo import MongoClient
client = MongoClient(‘localhost‘,27017)
#client = MongoClient(‘mongodb://localhost:27017‘)

访问数据库

当前所使用的数据库test的users

 

db = client.test
users = db.users
#或者db = client[‘users‘]

插入文档

文档就是一行，集合就是一个表

一个insert_one()

user1 = {"name":"li8","age":8}
rs = users.insert_one(user1)
print(‘one insert:{0}‘.format(rs.inserted_id))

多个 insert_many()

user2 = {"name":"li9","age":9}
user3 = {"name":"li10","age":10}
user4 = {"name":"li11","age":11}
user5 = {"name":"li12","age":12}
new_result = users.insert_many([user2, user3, user4, user5])
print(‘Multiple users: {0}‘.format(new_result.inserted_ids))

检索文档

一个find_one()

usertmp = users.find_one({"age":33})
print(usertmp)

多个find()

rs = users.find({‘age‘: 33})
for tmp in rs:
    print(tmp)

高级查询

rs = users.find({‘age‘:{"$lt":30}}).sort("name")
for tmp in rs:
    print(tmp)

统计数量

print(users.count())

加索引

from pymongo import ASCENDING, DESCENDING
print(users.create_index([("age", DESCENDING), ("name", ASCENDING)]))

 

MongoEngine是一个对象文档映射器（ODM），相当于一个基于SQL的对象关系映射器（ORM）

MongoEngine提供的抽象是基于类的，创建的所有模型都是类

 安装

pip install mongoengine

使用

from mongoengine import *
connect(‘test‘, host=‘localhost‘, port=27017)
import datetime
class Users(Document):
    name = StringField(required=True, max_length=200)
    age = IntField(required=True)

users = Users.objects.all()
for u in users:
    print("name:",u.name,",age:",u.age)

保存

from mongoengine import *
connect(‘test‘, host=‘localhost‘, port=27017)
import datetime
class Users(Document):
    name = StringField(required=True, max_length=200)
    age = IntField(required=True)
user1 = Users(
    name=‘zz‘,
    age= 11
)
user1.save()   
print(user1.name)
user1.name = ‘zz11‘
user1.save()       
print(user1.name)