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Python与MongoDB交互

article 2024/10/1 18:39:54

Python与MongoDB的交互通常通过pymongo库来实现。pymongo是一个官方的Python驱动程序，用于与MongoDB数据库进行交互。以下是一个简单的示例，展示了如何使用pymongo来连接到MongoDB数据库，执行一些基本的数据库操作（如插入、查询、更新和删除文档）。

安装pymongo

pip install pymongo

Python连接Mongodb

from pymongo import MongoClient

# 创建一个MongoClient对象，该对象用于连接Mongodb数据库服务器
client = MongoClient('mongodb://admin:password@localhost:27017/')

向数据库中添加数据

from mongo_db import client

# client.school.teacher.insert_one({"name": "露娜"})

# client.school.teacher.insert_many([{"name":"兰陵王"}, {"name": "百里玄策"}])

client.school.teacher.find({})

查询数据

from mongo_db import client

try:
    teachers = client.school.teacher.find()
    # print(teachers)
    for one in teachers:
        print(one["_id"],one["name"])

    # 有条件查询
    teacher = client.school.teacher.find_one({"name":"兰陵王"})
    print(teacher["_id"],teacher["name"])

except Exception  as e:
    print(e)

更新修改数据

from mongo_db import client

try:
    # 全表修改，表中无此列时会增加此列
    # client.school.teacher.update_many({}, {'$set': {"role":["班主任"]}})
    # client.school.teacher.update_one({"name": "露娜"},{"$set":{"sex": "女"}})

    # push追加(列表)
    client.school.teacher.update_one({"name": "露娜"},{"$push":{"role": "年级王主任"}})

except Exception as e:
    print(e)

删除数据

from mongo_db import client

try:
    # 有条件查询
    # client.school.teacher.delete_one({"name": "露娜"})
    # 删除多条数据
    client.school.teacher.delete_many({})
except Exception as e:
    print(e)

索引

创建索引以优化查询性能。

collection.create_index([("name", pymongo.ASCENDING)])

聚合框架

使用聚合框架进行复杂的数据聚合操作

pipeline = [
    {"$match": {"age": {"$gt": 25}}},
    {"$group": {"_id": "$city", "count": {"$sum": 1}}}
]
results = collection.aggregate(pipeline)
for result in results:
    print(result)

事务

从MongoDB 4.0开始，支持多文档事务，确保数据的一致性和完整性。

with client.start_session() as session:
    with session.start_transaction():
        collection.update_one({"name": "John"}, {"$set": {"age": 32}}, session=session)
        collection.update_one({"name": "Alice"}, {"$set": {"age": 26}}, session=session)
        session.commit_transaction()

关闭连接