魔坊APP项目-11-PyMongo、数据库连接，管理、集合管理、文档管理（添加文档、查询文档、删除文档、更新文档）

PyMongo

安装：

pip install pymongo

一、数据库连接

数据库连接，无密码

from pymongo import MongoClient

# 数据库链接，必须保证当前系统能正常访问mongodb!!!
connect = MongoClient('mongodb://127.0.0.1:27017/')

# 创建/切换数据库，数据库不存在则会库中有文档以后，自动创建
my_db = connect['mofang']
print(my_db)  # 数据库信息

# 创建/进入集合，集合不存在则会集合中有文档以后，自动创建
my_collections = my_db['my_collections']
print(my_collections)  # 集合信息

数据库连接，有密码

from pymongo import MongoClient
# 数据库链接，必须保证当前系统能正常访问mongodb!!!

"""方式1：如果帐号密码没有特殊字符"""
# connect = MongoClient('mongodb://mofang:123456@127.0.0.1:27017/mofang')

"""方式2：当前库的管理员连接"""
# from urllib import parse

# username = parse.quote_plus('mofang')  # 对用户名进行编码
# password = parse.quote_plus('123456')  # 对密码进行编码
# database = parse.quote_plus('mofang')  # 对数据库进行编码
# connect = MongoClient('mongodb://%s:%s@127.0.0.1:27017/%s' % (username, password, database))
# my_db = connect['mofang']
# my_collections = my_db['my_collections']

"""方式3：基于超级管理员身份连接，不需要当前库的管理员了"""
from urllib import parse
username = parse.quote_plus('root')  # 对用户名进行编码
password = parse.quote_plus('123')  # 对密码进行编码
database = parse.quote_plus('admin')  # 对数据库进行编码
connect = MongoClient('mongodb://%s:%s@127.0.0.1:27017/%s' % (username, password, database))
my_db = connect['mofang']
my_collections = my_db['my_collections']
# 添加一篇文档
data = {'name': 'xiaoming1号', 'sex': True, 'age':17}
ret = my_collections.insert_one(data)
print(ret.inserted_id)

二、数据库管理

from pymongo import MongoClient
# 数据库链接，必须保证当前系统能正常访问mongodb!!!

connect = MongoClient('mongodb://root:123@127.0.0.1:27017/admin')
my_db = connect['mofang']
my_collecctions = my_db['my_collections']

# 查看所有数据库[除了三个基本数据库以外，其他数据库只会显示有文档数据的]
ret = connect.list_database_names()
print(ret)  # ['admin', 'config', 'local', 'mofang']
ret = my_db.list_collection_names()
print(ret)  # ['my_collections']

# 数据库的删除,仅仅是清空所有集合就可以了

三、集合管理

from pymongo import MongoClient
# 数据库链接，必须保证当前系统能正常访问mongodb!!!

connect = MongoClient('mongodb://root:123@127.0.0.1:27017/admin')
my_db = connect['mofang']
my_collecctions = my_db['my_collections']

# 查看所有数据库[除了三个基本数据库以外，其他数据库只会显示有文档数据的]
# ret = connect.list_database_names()
# print(ret)  # ['admin', 'config', 'local', 'mofang']
# ret = my_db.list_collection_names()
# print(ret)  # ['my_collections']
# 删除集合的方式1
my_collecctions = my_db['notify_list']
my_collecctions.drop()

# 删除集合的方式2
my_db.drop_collection('notify_list')

四、文档管理

1.添加文档

from pymongo import MongoClient
# 数据库链接，必须保证当前系统能正常访问mongodb!!!
connect = MongoClient('mongodb://root:123@127.0.0.1:27017/admin')
my_db = connect['mofang']
my_collections = my_db['my_collections']

# 添加一条数据
document = {'name': 'xiaoming', 'mobile': '13012345678', 'age': 16, 'sex': True}
ret = my_collections.insert_one(document)
print(ret.inserted_id)  # 返回主键ID

# 添加多条数据
data_list = [
    { "name": "xiaobai", "mobile": "13322345678","age":16,"sex":False},
    { "name": "xiaohei", "mobile": "13322345678","age":20,"sex":True},
    { "name": "xiaohong", "mobile": "13322345678","age":13,"sex":False},
    { "name": "xiaolan", "mobile": "13322345678","age":17,"sex":True},
    { "name": "xiaolv", "mobile": "13322345678","age":17,"sex":True},
    { "name": "xiaolong", "mobile": "13322345678","age":16,"sex":False},
    { "name": "xiaofei", "mobile": "13322345678","age":18,"sex":True},
]
ret = my_collections.insert_many(data_list)
print(ret.inserted_ids)

2.查询文档

from pymongo import MongoClient

# 数据库链接，必须保证当前系统能正常访问mongodb
connect = MongoClient('mongodb://root:123@127.0.0.1:27017/admin')
my_db = connect['mofang']
my_collections = my_db['my_collections']

"""获取一条"""
# document = my_collections.find_one()
# print(document)  # {'_id': ObjectId('5fd21237d883925209b60067'), 'name': 'xiaoming1号', 'sex': True, 'age': 17}
# 获取数据中的信息
# print(document['name'])  # xiaoming1号

"""获取多条数据"""
# document_list = my_collections.find()
# print(document_list)
# for document in document_list:
#     print(document)
#     print(document['_id'])

"""字段投影：只显示部分字段，1表示显示，0表示隐藏"""
# document_list = my_collections.find({}, {'name': 1, '_id': 0})
# for document in document_list:
#     print(document)

"""基于查询条件获取数据"""
# 值相等
# query = {'name': {'$eq': 'xiaoming'}}
# query = {'name': 'xiaoming'}
# document = my_collections.find_one(query)
# print(document)  # {'_id': ObjectId('5fd2184326c8493bb4e2ace3'), 'name': 'xiaoming', 'mobile': '13012345678', 'age': 16, 'sex': True}

"""
query = {"age":{"$gt":17}}    age  >  17
query = {"age":{"$gte":17}}    age >= 17
query = {"age":{"$lte":17}}    age <= 17
query = {"age":{"$lt":17}}    age  <  17
query = {"age":{"$ne":17}}    age  != 17
query = {"age":{"$in":[16,17]}}    age in [16,17]
"""
# query = {'age': {'$in': [16, 18]}}
# document_list = my_collections.find(query)
# for document in document_list:
#     print(document)

"""排序"""
"""
单个字段：
    sort("age",-1) # 倒序
    sort("age",1)  # 升序
多个字段：
    sort([("age",-1),("_id",1)])
"""
# document_list = my_collections.find().sort('age', -1)
# document_list = my_collections.find().sort([('age', -1), ('_id', 1)])
# for document in document_list:
#     print(document)

"""限制结果"""
document_list = my_collections.find().limit(3)
for document in document_list:
    print(document)

3.删除文档

from pymongo import MongoClient
# 数据库链接，必须保证当前系统能正常访问mongodb
connect = MongoClient('mongodb://root:123@127.0.0.1:27017/admin')
my_db = connect['mofang']
my_collections = my_db['my_collections']

"""删除文档"""
# 删除一个文档
query = {'name': 'xiaoming'}
ret = my_collections.delete_one(query)
print(ret.deleted_count)  # 1:删除成功 0:没有删除的数据

# 删除多个文档
query = {'name': 'xiaoming1号'}
ret = my_collections.delete_many(query)
print(ret.deleted_count)  # 大于0:删除成功 0:没有删除的数据

# 查询一条数据出来并删除
# 返回一条数据，如果没有，则返回None
query = {'name': 'xiaobai'}
document = my_collections.find_one_and_delete(query)
print(document)  # {'_id': ObjectId('5fd218accf506de09fbecd68'), 'name': 'xiaobai', 'mobile': '13322345678', 'age': 16, 'sex': False}

4.更新文档

from pymongo import MongoClient
# 数据库链接，必须保证当前系统能正常访问mongodb
connect = MongoClient('mongodb://root:123@127.0.0.1:27017/admin')
my_db = connect['mofang']
my_collections = my_db['my_collections']

"""更新文档"""
"""按条件更新一个文档的指定数据"""
query = {'name': 'xiaofei'}
upsert = {'$set': {'age': 22}}
ret = my_collections.update_one(query, upsert)
print(ret.modified_count)  # 0 表示没有任何修改，1表示修改成功

"""按条件累加/累减指定数值一个文档的指定数据"""
query = {'name': 'xiaofei'}
upsert = {'$inc': {'age': -1}}  # 累减
upsert = {'$inc': {'age': 1}}  # 累加
ret = my_collections.update_one(query, upsert)
print(ret.modified_count)

"""更新多条数据"""
# 把所有以"133"开头的手机码号的文档，全部改成15012345678
query = {'mobile': {'$regex': '^133'}}
upsert = {'$set': {'mobile': '15012345678'}}
ret = my_collections.update_many(query, upsert)
print(ret.modified_count)

本文地址：https://blog.csdn.net/qq_45957580/article/details/111004227