pymongo

Posted 2021-02-03 baijinshuo

python操作MongoDB,需要安装模块 pymongo

pip install pymongo

 连接

新建一个文件 test_mongo.py

import pymongo

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建

res = mongo_db.goods.find()
print(res)

 

执行输出：

<pymongo.cursor.Cursor object at 0x000001F68B7D09E8>

插入数据

import pymongo

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建

# 插入多条数据
res = mongo_db.goods.insert_many([{"name" : "酸菜","price" : "1"},{"name" : "白菜","price" : "2"},{"name" : "小青菜","price" : "0.5"},])
print(res)

 查询数据

查询所有

可以将结果转换为列表

import pymongo

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建

# 插入多条数据
res = mongo_db.goods.find()
print(list(res))

 

执行输出：

[{‘_id‘: ObjectId(‘5b991895e125324a58178dd3‘), ‘name‘: ‘酸菜‘, ‘price‘: ‘1‘}, {‘_id‘: ObjectId(‘5b991895e125324a58178dd4‘), ‘name‘: ‘白菜‘, ‘price‘: ‘2‘}, {‘_id‘: ObjectId(‘5b991895e125324a58178dd5‘), ‘name‘: ‘小青菜‘, ‘price‘: ‘0.5‘}]

 也可以对结果做for循环

import pymongo

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建

# 插入多条数据
res = mongo_db.goods.find()
for i in res:
    print(i)

 

执行输出：

{‘_id‘: ObjectId(‘5b991895e125324a58178dd3‘), ‘name‘: ‘酸菜‘, ‘price‘: ‘1‘}
{‘_id‘: ObjectId(‘5b991895e125324a58178dd4‘), ‘name‘: ‘白菜‘, ‘price‘: ‘2‘}
{‘_id‘: ObjectId(‘5b991895e125324a58178dd5‘), ‘name‘: ‘小青菜‘, ‘price‘: ‘0.5‘}

 查询单条

import pymongo

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建

# 插入多条数据
res = mongo_db.goods.find_one()
print(res)

 

执行输出：

{‘_id‘: ObjectId(‘5b991895e125324a58178dd3‘), ‘name‘: ‘酸菜‘, ‘price‘: ‘1‘}

 

查询指定id呢？

由于_id是ObjectId对象，需要导入模块

import pymongo
from bson import ObjectId

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建

# 插入多条数据
res = mongo_db.goods.find({"_id":ObjectId("5b991895e125324a58178dd5")})
for i in res:
    print(i)

 

执行输出：

{‘_id‘: ObjectId(‘5b991895e125324a58178dd5‘), ‘name‘: ‘小青菜‘, ‘price‘: ‘0.5‘}

 更新

import pymongo
from bson import ObjectId

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建


res = mongo_db.goods.update_one({"name":"小青菜"},{"$set":{"price":2}})
print(res)

 

执行输出：

<pymongo.results.UpdateResult object at 0x000001AF61E332C8> None

 删除

import pymongo
from bson import ObjectId

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建


res = mongo_db.goods.delete_one({"name":"小青菜"})
print(res,res.raw_result)

 

执行输出：

<pymongo.results.DeleteResult object at 0x000001825B2134C8> {‘n‘: 0, ‘ok‘: 1.0}

 排序

import pymongo
from bson import ObjectId

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建


res = mongo_db.goods.find({}).skip(1).limit(2)
print(list(res))

 

执行输出：

[{‘_id‘: ObjectId(‘5b991895e125324a58178dd4‘), ‘name‘: ‘白菜‘, ‘price‘: ‘2‘}]

 

进阶

import pymongo
from bson import ObjectId

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建


res = mongo_db.goods.find({}).sort("age",pymongo.DESCENDING)
print(list(res))

 

执行输出：

[{‘_id‘: ObjectId(‘5b991895e125324a58178dd3‘), ‘name‘: ‘酸菜‘, ‘price‘: ‘1‘}, {‘_id‘: ObjectId(‘5b991895e125324a58178dd4‘), ‘name‘: ‘白菜‘, ‘price‘: ‘2‘}]

 

高级操作

import pymongo
from bson import ObjectId

# 连接数据库
mclient = pymongo.MongoClient(host="127.0.0.1", port=27017)
mongo_db = mclient["testdb"]  # 切换数据库,不存在则创建


res = mongo_db.goods.find({}).sort("age",pymongo.DESCENDING).skip(1).limit(2)
print(list(res))

 

执行输出：

[{‘_id‘: ObjectId(‘5b991895e125324a58178dd4‘), ‘name‘: ‘白菜‘, ‘price‘: ‘2‘}]