简体中文（ZH-CN）English（EN）繁体中文（ZH-TW）日本語（JA）한국어（KO）Melayu（MS）Français（FR）Deutsch（DE）
Home
Article
Q&A
Course
Topic
Download
Game
Dictionary
Recent Updates

Home  >  Article  >  Backend Development  >  How to operate MongoDB database with Python

How to operate MongoDB database with Python

WBOY
WBOYforward
2023-05-28 09:31:102765browse

1. Connector installation and configuration

pymongo: The Python toolkit officially provided by MongoDB. Official documentation: https://pymongo.readthedocs.io/en/stable/ pip installation, the command is as follows: 

pip install pymongo

Main steps to manage MongoDB As follows:

  • Connect to the MongoDB database system

  • Manage the MongoDB database

  • Management Collections in MongoDB

  • Manage documents in MongoDB

The first step is to connect to MongoDB: 

# 方式一: 使用默认的配置
client = MongoClient()
# 方式二: 指定主机地址和端口号
client = MongoClient('localhost', 27017)
# 方式三: 使用URI连接参数
client = MongoClient('mongodb://localhost:27017/')

The second step, manage the database: 

#通过MongoClient对象来管理多个数据库获取数据库(逻辑库)对象
db = client.DATABASE_NAME
db = client["DATABASE_NAME"]
db = client.get_database(name=None, *args)
# 查看所有的数据库(逻辑库)
client.list_databases()
# 删除数据库(逻辑库)
client.drop_database(name_or_database, *args)

The third step, manage the collection

# 通过数据库对象db来管理集合
# 获取集合对象
db = client.DATABASE_NAME
db.COLLECTION_NAME
client.DATABASE_NAME.COLLECTION_NAME
db.get_collection(name, *args)
# 查看当前数据库下的集合列表
db.list_collection_names()
# 删除集合
db.drop_collection(name_or_collection, *args)

Basic operation example:

# -*- coding: utf-8 -*-
# @Time    : 2023-03-17 1:47
# @Author  : AmoXiang
# @File    : 1.数据库连接.py
# @Software: PyCharm
# @Blog    : https://blog.csdn.net/xw1680

from pymongo import MongoClient

# 使用默认配置连接到数据库
# client = MongoClient()
# print(client)
# client.close()
# 指定主机地址和端口号连接到数据库
# client = MongoClient('localhost', 27017)
# 使用URI连接参数连接到数据库
client = MongoClient('mongodb://localhost:27017/')
print(client)
# client.close()
#
# # 访问数据库
# db = client.test
# db = client["test"]
# print(db)
# db = client.get_database('test')
# client.close()
# print(db)
#
# 查看有哪些数据库
db_list = client.list_databases()
# # db_list = client.list_database_names()
for item in db_list:
    print(item)
#
# 查看数据库下有哪些集合
db_test = client["test"]
for item in db_test.list_collection_names():
    print(item)
#
# # 集合对象操作
# data = db_test.students.find_one()
# data = client.test.students.find_one()
data = client.test.get_collection('students').find_one()
print(data)

2. New document

Description: pymongo can convert python objects into BSON when inserting data

insert_one(): Insert a document

# 调用方法
result = db.COLLECTION_NAME.insert_one(doc)
# 返回插入的文档ID
result.inserted _id

insert_many(): Add documents in batches. Calling method: 

doc_list = [doc1,doc2]
result = db.COLLECTION_NAME.insert_many(doc_list)

Example:

3. Query documents

pymongo can convert the query results into objects in python

Common methods: 

find_one(): 按条件查询一个文档
find(): 按条件查询多个文档
count_documents(): 统计满足条件的文档总数
aggregate(): 聚合统计
.sort(): 排序
.skip().limit(): 分页

Sample code: 

# -*- coding: utf-8 -*-
# @Time    : 2023-03-18 15:03
# @Author  : AmoXiang
# @File    : 5.查询文档.py
# @Software: PyCharm
# @Blog    : https://blog.csdn.net/xw1680

from bson.objectid import ObjectId
from pymongo import MongoClient, ASCENDING, DESCENDING


class LearnMongoDBSearch(object):
    """ MongoDB查询练习 """

    def __init__(self):
        self.client = MongoClient()

    def search_one(self):
        """ 查询一个文档 """
        temp_obj = self.client.test.newdb.find_one()
        print(temp_obj)
        print('喜欢分数：', temp_obj['likes'])
        # print('注册时间：', temp_obj['reg_date'].date())
        print('姓名：', temp_obj['uname'])

    def search_user_by_pk(self, pk):
        obj_id = ObjectId(pk)
        # user_obj = self.client.test.newdb.find_one({'_id': obj_id})
        # 面向对象的方法，有代码提示
        db = self.client.get_database('test')
        users = db.get_collection('newdb')
        user_obj = users.find_one({'_id': obj_id})
        print(user_obj)

    def search_many(self):
        """ 查询多个文档 """
        db = self.client.get_database('test')
        students = db.get_collection('students')
        # stu_list = students.find()
        # for item in stu_list:
        #     print(item)

        # 查询年龄大于12岁的学生
        stu_list = students.find({'age': {'$gt': 12}}, {'stu_name': 1, 'class_name': 1, 'age': 1})
        for item in stu_list:
            # 注意:  mongo中存储的整数转换成了浮点数
            print(item)

    def paginate(self, page=1, page_size=10):
        """
        分页处理
        :param page: 当前的页
        :param page_size: 每一页数据大小
        :return:
        """
        db = self.client.get_database('test')
        students = db.get_collection('students')
        offset = (page - 1) * page_size
        stu_list = students.find().skip(offset).limit(page_size)
        return stu_list

    def sort_data(self):
        """ 排序 """
        db = self.client.get_database('test')
        grades = db.get_collection('grades')
        # // 将学生的语文成绩从高到低排序
        # db.grades.find({"grade.course_name": "语文"}).sort({"grade.score": -1});
        #
        # //将学生的语文成绩按照年龄和成绩排序
        # db.grades.find({"grade.course_name": "语文"}).sort({"age": -1, "grade.score": -1});
        # db.grades.find({"grade.course_name": "语文"}).sort({"grade.score": -1, "age": -1});

        # 按某一列排序
        # data_list = grades.find({"grade.course_name": "语文"}).sort("grade.score", DESCENDING);
        # for item in data_list:
        #     print(item)

        # 按多列排序
        data_list = grades.find({"grade.course_name": "语文"}).sort([('age', DESCENDING),("grade.score", DESCENDING),])
        for item in data_list:
            print(item)

    def counter_students(self):
        """ 统计newdb中文档总数 """
        db = self.client.get_database('test')
        newdb = db.get_collection('newdb')
        # result = newdb.count_documents({})
        result = newdb.count_documents({"uname": {"$eq": "张三"}})
        print(result)

    def test_aggregate(self):
        """
        聚合统计：及格的学生成绩
        """
        db = self.client.get_database('test')
        grades = db.get_collection('grades')
        result = grades.aggregate([
            # //where
            {
                '$match': {"grade.score": {'$gte': 60}}
            },
            # //group by
            {
                '$group': {
                    '_id': "$stu_no",
                    'total': {'$sum': 1}
                }
            },
            # // having
            {
                '$match': {
                    'total': {'$eq': 3}
                }
            }
            ])
        for item in result:
            print(item)


if __name__ == '__main__':
    obj = LearnMongoDBSearch()
    # obj.search_one()
    # obj.search_user_by_pk('6411ee77b6170000b4003f95')
    # obj.search_many()
    # stu_list = obj.paginate(page=3)
    # for item in stu_list:
    #     print(item)

    # obj.sort_data()
    # obj.counter_students()
    obj.test_aggregate()

4. Update the document

Review, update the data expression, as shown in the following table:

How to operate MongoDB database with Python

Modify a document and call the method: 

update_one(filter, update, *args)

Replace a document and call the method: 

replace_one(filter, replacement, *args)

Modify documents in batches and call the method: 

replace_one(filter, replacement, *args)

Shortcut method: 

find_one_and_update(filter, update, *args)  # 修改一个文档
find_one_and_replace(filter, replacement, *args)  # 替换一个文档
# 注意返回值的不同

Return results:

acknowledged: whether the result has been confirmed
modified_count: the number of modified documents
matched_count: the number of documents that meet the conditions
raw_result: original data
upserted_id: updated ID (upsert=True)

Sample code: 

# -*- coding: utf-8 -*-
# @Time    : 2023-03-18 14:56
# @Author  : AmoXiang
# @File    : 4.修改文档.py
# @Software: PyCharm
# @Blog    : https://blog.csdn.net/xw1680

from pymongo import MongoClient

class LearnMongoDBUpdate(object):
    """ MongoDB更新练习 """

    def __init__(self):
        self.client = MongoClient()

    def test_update_one(self):
        """ 更新一个文档 """
        db = self.client.get_database('test')
        newdb = db.get_collection('newdb')
        result = newdb.update_one({}, {'$set': {'likes': 70}})
        print(result.modified_count)

    def test_replace_one(self):
        """ 替换一个文档 """
        db = self.client.get_database('test')
        newdb = db.get_collection('newdb')
        result = newdb.replace_one({}, {'uname': '张三'})
        print(result.modified_count)

    def test_update_many(self):
        """ 批量更新文档 """
        db = self.client.get_database('test')
        newdb = db.get_collection('newdb')
        result = newdb.update_many({}, {'$set': {'likes': 90}})
        print('修改的数量：', result.modified_count)
        print('满足条件的数量：', result.matched_count)

    def test_update_shortcut(self):
        """ 更新文档的快捷方法 """
        db = self.client.get_database('test')
        newdb = db.get_collection('newdb')
        # 此处返回一个文档对象
        result = newdb.find_one_and_update({}, {'$set': {'sex': '未知'}})
        print(result['_id'])
if __name__ == '__main__':
    obj = LearnMongoDBUpdate()
    # obj.test_update_one()
    # obj.test_replace_one()
    # obj.test_update_many()
    obj.test_update_shortcut()

5. Delete documents

To delete a document, the calling method is as follows: 

result = db.COLLECTION_NAME.delete_one(filter, *args)
# 返回已经删除的记录数 result.deleted_count
# 删除时返回文档对象 
find_one_and_delete(filter, *args)

To delete documents in batches, the calling method is: 

result = db.COLLECTION_NAME.delete_many(filter, *args)
# 返回已经删除的记录数
result. deleted_count

Example Code: 

# -*- coding: utf-8 -*-
# @Time    : 2023-03-18 14:34
# @Author  : AmoXiang
# @File    : 3.删除文档.py
# @Software: PyCharm
# @Blog    : https://blog.csdn.net/xw1680

from pymongo import MongoClient


class LearnMongoDBDelete(object):
    """ MongoDB删除练习 """

    def __init__(self):
        self.client = MongoClient()

    def test_delete_one(self):
        """ 删除一个文档 """
        db = self.client.get_database('test')
        newdb = db.get_collection('newdb')
        result = newdb.delete_one({})
        print(result.deleted_count)

    def test_delete_many(self):
        """ 批量删除文档 """
        db = self.client.get_database('test')
        users = db.get_collection('newdb')
        # 删除所有的数据
        result = users.delete_many({"likes": {"$lte": 90}})
        print(result.deleted_count)

    def test_delete_shortcut(self):
        """ 删除文档的快捷方法 """
        db = self.client.get_database('test')
        newdb = db.get_collection('newdb')
        result = newdb.find_one_and_delete({})
        print(result['title'])


if __name__ == '__main__':
    obj = LearnMongoDBDelete()
    # obj.test_delete_one()
    # obj.test_delete_shortcut()
    obj.test_delete_many()

The above is the detailed content of How to operate MongoDB database with Python. For more information, please follow other related articles on the PHP Chinese website!

Python pip 对象 mongodb 数据库 https
Statement：
This article is reproduced at:yisu.com. If there is any infringement, please contact admin@php.cn delete
Previous article：Thanks to learning this Python library, I eliminated a pyramid scheme in one night...Next article：Thanks to learning this Python library, I eliminated a pyramid scheme in one night...

Related articles

See more