Python 使用MongoDB

补充：操作之前首先在虚拟机或者服务器端启动 MongoDB ;

# 重新加载配置，并启动mongodb
sudo systemctl daemon-reload
sudo systemctl start mongod

# 查看运行状态
sudo systemctl status mongod
# 如果mongodb状态为stop，则运行 sudo systemctl enable mongod

# 停止mongodb
sudo systemctl stop mongod

# 重启mongodb
sudo systemctl restart mongod

1.介绍与安装

在 Python 当中，一般常用于开发中操作 MongoDB 的模块无非三个:pymongo,mongoengine,moter

moter 是 python 中基于 pymongo 实现的异步操作，类似于aiomysql基于pymysql实现异步操作.

• 安装

  pip install pymongo
  

2.数据库连接

• 无密码连接

  import pymongo
  
  mongo = pymongo.MongoClient("mongodb://192.168.127.129:27017")
  

• 有密码连接

  方式一

  import pymongo
  from urllib.parse import quote_plus
  
  username = quote_plus("mofang")
  password = quote_plus("1234567")
  # 获取连接对象:字符串 mongodb 引擎 + // 用户名:密码@地址:端口/库名
  mongo = pymongo.MongoClient(f"mongodb://{username}:{password}@192.168.127.129:27017/mofang")
  # print(mongo)
  # 获取数据库操作对象
  db = mongo['mofang']
  print(db)
  # 获取集合操作对象
  collection = db['user_list']
  print(collection)
  

  方式二

  # 方式二
  import pymongo
  mongo = pymongo.MongoClient("mongodb://127.0.0.1:27017")
  db = mongo['mofang']
  username = "mofang"
  password = "1234567"
  v = db.authenticate(username,password)
  print(db)
  print(v)
  # collection = db['user_list']
  # print(collection)
  

  补充：方式二可能对于较新的版本会失效,可以回退版本解决出现的问题.

  import pymongo
  conn = pymongo.MongoClient(host="192.168.127.129",port=27017)
  mongo = conn['mofang']
  mongo.authenticate("mofang","1234567")
  # 上述的字符串也可以使用参数进行替代,但是这种认证方式不支持pymongo4.0 以后的版本
  

3.pymongo的封装

pymongo 的操作很多会受到版本的困扰,使用的时候请确定版本信息进行一定的修改；

# -*- coding: utf-8 -*-
"""封装 MongoDB 的数据库的操作信息;
注: 本工具依赖包是 pymongo == 3.12.3; 更高版本的包可能会导致方法的出错
"""
import pymongo

from config.settings import MONGODB


class MongoHelper(object):
    """封装 MongoDB 的基本操作
    """

    def __init__(self):
        """实例化 MongoDB 的连接池对象,使用对象进行 MongoDB 的操作;
        """
        if MONGODB.get("password") is None:
            url = "mongodb://%(host)s:%(port)s" % {
                "host": MONGODB['host'],
                "port": MONGODB['port'],
            }
        else:
            # 扩展有密码时连接的配置信息;
            url = "mongodb://%(user)s:%(password)s@%(host)s:%(port)s" % {
                "user": MONGODB["user"],
                "password": MONGODB["password"],
                "host": MONGODB["host"],
                "port": MONGODB["port"]
            }
        # 将线程安全的连接池封装到对象中;
        self.connect_client = pymongo.MongoClient(url)

    def close_connect(self):
        """
        关闭 mongodb 的连接;
        :return: None
        """
        self.connect_client.close()

    def get_connections(self) -> list:
        """
        获取数据库中的集合信息;
        :return: list; 集合名称的列表信息;

        example:
            v = mongo_helper.get_connections()
            print(v)
        """
        result = self.connect_client[MONGODB['database']].list_collection_names()
        self.close_connect()
        return result

    def insert_one(self, collection_name: str, value: dict):
        """
        向集合中插入一条(文档)数据;
        :param collection_name: str; 集合的名称;
        :param value: 被插入的数据信息;
        :return: 返回插入返回的 id 信息

        example:
            v = mongo_helper.insert_one('test', {"name": "hello", "price": 33})
            print(v)
        """
        conn = self.connect_client[MONGODB['database']]
        col_insert = conn[collection_name].insert_one(value)
        col_id = col_insert.inserted_id
        self.close_connect()
        return col_id

    def insert_many(self, collection_name: str, value: list):
        """
        插入多条数据信息;
        :param collection_name: 集合的名称;
        :param value: 列表嵌套字典的信息;
        :return: 返回插入的 ids 对象集合的列表信息;

        example:
            data = [
                {"name": "前端", 'price': 66},
                {"name": "前端", 'price': 66},
                {"name": "前端", 'price': 66},
                {"name": "前端", 'price': 66},
                {"name": "前端", 'price': 66},
                {"name": "前端", 'price': 66}
            ]
            v = mongo_helper.insert_many('test', data)
            print(v)
        """
        conn = self.connect_client[MONGODB['database']]
        col_insert = conn[collection_name].insert_many(value)
        col_ids = col_insert.inserted_ids
        self.close_connect()
        return col_ids

    def fetch_one(self, collection_name: str, filters: dict = None) -> dict:
        """
        查询一条符合条件的数据信息
        :param collection_name: 集合的名称;
        :param filters: dict; 过滤条件;
        :return: dict; 筛选结果,字典信息;

        example:
            filters = {"name": "python入门"}
            v = mongo_helper.fetch_one("test", filters)
            print(v)

        """
        conn = self.connect_client[MONGODB['database']][collection_name]
        result = conn.find_one(filters)
        self.close_connect()
        return result

    def fetch_all(self, collection_name: str, filters: dict = None) -> list:
        """
        查询符合条件的所有数据信息,将游标的信息进行循环获取到列表信息;
        :param collection_name: 集合的名称;
        :param filters: dict; 过滤的条件信息;
        :return: list; 符合条件的数据列表

        example:
            filters = {"name": "java入门"}
            v = mongo_helper.fetch_all("test", filters)
            print(v, type(v))

        """
        conn = self.connect_client[MONGODB['database']][collection_name]
        result = conn.find(filters)  # 此时返回的是游标对象;
        result_list = [i for i in result]
        self.close_connect()
        return result_list

    def fetch_page_info(self, collection_name: str, filters: dict = None, page_size: int = 10,
                        page_no: int = 1) -> dict:
        """
        分页查询的使用;
        :param collection_name: 集合的名称信息;
        :param filters: 查询条件信息;
        :param page_size: 每页上的数量信息;
        :param page_no: 页码信息;
        :return: dict; 返回分页查询的信息数据;

        example:
            filters = {"name": "java入门"}
            v = mongo_helper.fetch_page_info("test", filters, 5, 5)
            print(v)
        """
        conn = self.connect_client[MONGODB['database']][collection_name]
        skip = page_size * (page_no - 1)
        result = conn.find(filters).limit(page_size).skip(skip)
        result_dict = {"page_size": page_size, "page_no": page_no, "data": [i for i in result]}
        self.close_connect()
        return result_dict

    def fetch_count_info(self, collection_name: str, filters: dict = None) -> int:
        """
        查询统计集合中的文档的数量信息;
        :param collection_name: str; 集合的名称;
        :param filters: dict; 按条件统计,为空的时候查询全部的信息;
        :return: int; 集合中的文档的数量信息;

        example:
            v = mongo_helper.fetch_count_info("test")
            print(v, type(v))
        """
        if filters is None:
            filters = {}
        conn = self.connect_client[MONGODB['database']][collection_name]
        result = conn.count_documents(filters)
        self.close_connect()
        return result

    def update_one(self, collection_name: str, filters: dict, data: dict) -> int:
        """
        更新一条文档的信息;
        :param collection_name: 集合的名称;
        :param filters: dict; 筛选条件;
        :param data: 修改的信息;
        :return: int; 返回被修改的文档数;

        example:
            filters = {"name": "java入门"}
            v = mongo_helper.update_many("test", filters, {"$set": {"name": "我爱学习"}})
            print(v, type(v))
        """
        conn = self.connect_client[MONGODB['database']][collection_name]
        result = conn.update_one(filter=filters, update=data)
        self.close_connect()
        return result.modified_count

    def update_many(self, collection_name: str, filters: dict, data: dict) -> int:
        """
        批量修改数据;
        :param collection_name: 集合的名称;
        :param filters: 筛选条件;
        :param data: 修改信息;
        :return: int; 修改的数量;

        example:
            filters = {"name": "我爱学习"}
            v = mongo_helper.update_many("test", filters, {"$set": {"name": "批量修改回来"}})
            print(v, type(v))
        """
        conn = self.connect_client[MONGODB['database']][collection_name]
        result = conn.update_many(filter=filters, update=data)
        self.close_connect()
        return result.modified_count

    def delete_one(self, collection_name: str, filters: dict) -> int:
        """
        删除单条的数据信息;
        :param collection_name:
        :param filters:
        :return: int; 删除数据的条数;

        example:
            filters = {"name": "批量修改回来"}
            v = mongo_helper.delete_one("test", filters)
            print(v, type(v))
        """
        conn = self.connect_client[MONGODB['database']][collection_name]
        result = conn.delete_one(filter=filters)
        self.close_connect()
        return result.deleted_count

    def delete_many(self, collection_name: str, filters: dict) -> int:
        """
        删除多条的数据信息;
        :param collection_name: 集合的名称;
        :param filters: dict; 过滤条件;
        :return: int; 返回删除的条数;

        example:
            filters = {"name": "批量修改回来"}
            v = mongo_helper.delete_many("test", filters)
            print(v, type(v))

        """
        conn = self.connect_client[MONGODB['database']][collection_name]
        result = conn.delete_many(filter=filters)
        self.close_connect()
        return result.deleted_count

    def drop_collection(self, collection_name: str):
        """
        删除集合(删除表);
        :param collection_name: 集合的名称;
        :return: None

        example:
            mongo_helper.drop_collection("test_data")
        """
        self.connect_client[MONGODB['database']][collection_name].drop()
        self.close_connect()


# 使用的时候为保持连接池的数量,导入时直接导入该对象进行单例模式形式的使用
mongo_helper = MongoHelper()

if __name__ == '__main__':
    """简单的脚本测试
    """
    v = mongo_helper.fetch_count_info("test")
    print(v)

继续努力,终成大器;