使用pymongo管理MongoDB

标签：教程 num 管理 MongoDB study client pymongo id desc

基于pymongo的MongoDB系列操作，会不定时补充更新

from pymongo import MongoClient
import pymongo
import datetime

## 连接本地 MongoDB
client = MongoClient("mongodb://localhost:27017/") #本地库参数可省缺

## 数据库名
client.list_database_names()

['admin', 'config', 'local', 'study']

## 集合（表）名
client.study.list_collection_names()

['mongo_study_sites']

零、MongoDB结构

MongoDB

database_1 数据库1
……
database_n 数据库n

collection_1 表1
……
collection_2 表n

document_1 行数据1
……
document_n 行数据n

一、增

## 1、新增数据库、集合（插入文档即创建，是无法创建空库空集合的）
docs = {'num': 1,
       'desc': '菜鸟教程：MongoDB教程',
       'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
client.study.mongo_study_sites.insert_one(docs) # 新增一条文档

for i in client.study.mongo_study_sites.find():
    print(i)

{'_id': ObjectId('61d6ea09082b9beb7bca8b08'), 'num': 1, 'desc': '菜鸟教程：MongoDB教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}

## 2、新增文档：同时插入多条文档 Bulk Inserts
docs_list = [{'num': 1,
              'desc': 'MongoDB菜鸟教程',
              'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'},
             {'num': 2,
              'desc': 'PyMongo官方教程',
              'url': 'https://pymongo.readthedocs.io/en/stable/index.html',
              'date': datetime.datetime(2022, 1, 5, 23, 8)},
             {'num': 3,
              'desc': 'PyMongo菜鸟教程',
              'url': 'https://www.runoob.com/python3/python-mongodb.html'}
            ]
client.study.mongo_study_sites.insert_many(docs_list)

for i in client.study.mongo_study_sites.find():
    print(i)

{'_id': ObjectId('61d6ea09082b9beb7bca8b08'), 'num': 1, 'desc': '菜鸟教程：MongoDB教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
{'_id': ObjectId('61d6ea09082b9beb7bca8b09'), 'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
{'_id': ObjectId('61d6ea09082b9beb7bca8b0a'), 'num': 2, 'desc': 'PyMongo官方教程', 'url': 'https://pymongo.readthedocs.io/en/stable/index.html', 'date': datetime.datetime(2022, 1, 5, 23, 8)}
{'_id': ObjectId('61d6ea09082b9beb7bca8b0b'), 'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}

二、删

## 1、删除文档：一定要制定条件，即使删除全部数据也要输入参数 {}
# 删除一条文档
flter = {'desc': '菜鸟教程：MongoDB教程'}
client.study.mongo_study_sites.delete_one(flter)

# 同时删除所有符合条件文档
client.study.mongo_study_sites.delete_many(flter)

for i in client.study.mongo_study_sites.find():
    print(i)

{'_id': ObjectId('61d6ea09082b9beb7bca8b09'), 'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
{'_id': ObjectId('61d6ea09082b9beb7bca8b0a'), 'num': 2, 'desc': 'PyMongo官方教程', 'url': 'https://pymongo.readthedocs.io/en/stable/index.html', 'date': datetime.datetime(2022, 1, 5, 23, 8)}
{'_id': ObjectId('61d6ea09082b9beb7bca8b0b'), 'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}

## 2、删除集合
client['study']['mongo_study_sites'].drop()
client.study.list_collection_names()

[]

三、改

## 1、修改文档
# 修改一条文档
flter = {'desc': 'PyMongo官方教程'}
upd = {'$set': {'num': 100}}
client['study']['mongo_study_sites'].update_one(flter, upd)

# 修改多条文档
client['study']['mongo_study_sites'].update_many(flter, upd)

for i in client['study']['mongo_study_sites'].find({}, {'_id':0}):
    print(i)

print('= ' * 50)
# 注意：如果修改字段不存在，则新增字段
flter = {'desc': 'PyMongo官方教程'}
upd = {'$set': {'score': '8分'}} #'score'不存在
client['study']['mongo_study_sites'].update_one(flter, upd)

for i in client['study']['mongo_study_sites'].find({}, {'_id':0}):
    print(i)

{'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
{'num': 100, 'desc': 'PyMongo官方教程', 'url': 'https://pymongo.readthedocs.io/en/stable/index.html', 'date': datetime.datetime(2022, 1, 5, 23, 8)}
{'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
{'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
{'num': 100, 'desc': 'PyMongo官方教程', 'url': 'https://pymongo.readthedocs.io/en/stable/index.html', 'date': datetime.datetime(2022, 1, 5, 23, 8), 'score': '8分'}
{'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}

## 2、删除字段
flter = {'desc': 'PyMongo官方教程'}
upd = {'$unset': {'score': '8分'}} #删除score字段
client['study']['mongo_study_sites'].update_one(flter, upd)

for i in client['study']['mongo_study_sites'].find({}, {'_id':0}):
    print(i)

{'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
{'num': 100, 'desc': 'PyMongo官方教程', 'url': 'https://pymongo.readthedocs.io/en/stable/index.html', 'date': datetime.datetime(2022, 1, 5, 23, 8)}
{'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}

## 3、修改字段名称
flter = {'desc': 'PyMongo官方教程'}
upd = {'$rename': {'date': 'DT'}} #重命名date为DT
client['study']['mongo_study_sites'].update_one(flter, upd)

for i in client['study']['mongo_study_sites'].find({}, {'_id':0}):
    print(i)

{'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
{'num': 100, 'desc': 'PyMongo官方教程', 'url': 'https://pymongo.readthedocs.io/en/stable/index.html', 'DT': datetime.datetime(2022, 1, 5, 23, 8)}
{'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}

四、查

## 1、查询全部find()、查询一条find_one()
flter = {'num': 3}
for i in client.study.mongo_study_sites.find(flter, {'_id':0, 'desc':1, 'url':1}):  # 指定查询字段
    print(i)
    
print('= ' * 50)

for i in client['study']['mongo_study_sites'].find_one(flter):
    print(i)

{'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
_id
num
desc
url

## 2、查询存在某个字段的文档
flter = {'DT': {'$exists': True}}
for i in client.study.mongo_study_sites.find(flter, {'_id':0}):  # 指定查询字段
    print(i)

{'num': 100, 'desc': 'PyMongo官方教程', 'url': 'https://pymongo.readthedocs.io/en/stable/index.html', 'DT': datetime.datetime(2022, 1, 5, 23, 8)}

## 3、比较查询
# $eq 等于
# $ne 不等于
# $gt 大于
# $gte 大于等于
# $lt 小于
# $lte 小于等于
# $in 存在于
# $nin 不存在于
flter = {'num': {'$gte': 2}}
for i in client.study.mongo_study_sites.find(flter, {'_id':0}):  # 指定查询字段
    print(i)
    
print('= ' * 50)

flter = {'num': {'$in': [1,3]}}
for i in client.study.mongo_study_sites.find(flter, {'_id':0}):  # 指定查询字段
    print(i)

{'num': 100, 'desc': 'PyMongo官方教程', 'url': 'https://pymongo.readthedocs.io/en/stable/index.html', 'DT': datetime.datetime(2022, 1, 5, 23, 8)}
{'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
{'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
{'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}

## 4、逻辑查询
# $and 且
# $or 或
# $not 非
# $nor
flter = {'$or':[{'desc': 'PyMongo菜鸟教程'}, {'num': 1}]}
for i in client.study.mongo_study_sites.find(flter, {'_id':0}):  # 指定查询字段
    print(i)

{'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
{'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}

## 5、正则表达式
flter = {'desc': {'$regex': r'菜鸟教程$'}} #desc以“菜鸟教程”结尾
for i in client.study.mongo_study_sites.find(flter, {'_id':0}):  # 指定查询字段
    print(i)

{'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}
{'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}

## 6、指定返回文档数
flter = {'desc': {'$regex': r'菜鸟教程$'}} #desc以“菜鸟教程”结尾
for i in client.study.mongo_study_sites.find(flter, {'_id':0}).limit(1):  # 指定查询字段
    print(i)

{'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}

## 7、排序
for i in client.study.mongo_study_sites.find({}, {'_id':0}).sort('num',-1):  # -1倒序，1（或省缺）正序
    print(i)

{'num': 100, 'desc': 'PyMongo官方教程', 'url': 'https://pymongo.readthedocs.io/en/stable/index.html', 'DT': datetime.datetime(2022, 1, 5, 23, 8)}
{'num': 3, 'desc': 'PyMongo菜鸟教程', 'url': 'https://www.runoob.com/python3/python-mongodb.html'}
{'num': 1, 'desc': 'MongoDB菜鸟教程', 'url': 'https://www.runoob.com/mongodb/mongodb-tutorial.html'}

五、聚合操作

## 0、创建数据集
docs_list = [{'name':'张三', 'age': 26, 'sex':'男', 'company':'A公司', 'income':6000},
             {'name':'李四', 'age': 30, 'sex':'男', 'company':'B公司', 'income':5000},
             {'name':'小红', 'age': 25, 'sex':'女', 'company':'A公司', 'income':5500},
             {'name':'王二', 'age': 26, 'sex':'男', 'company':'A公司', 'income':9000},
             {'name':'小芳', 'age': 26, 'sex':'女', 'company':'B公司', 'income':7000}]

client['study']['employee'].insert_many(docs_list)
for i in client['study']['employee'].find({}):
    print(i)

{'_id': ObjectId('61d70149082b9beb7bca8b1b'), 'name': '张三', 'age': 26, 'sex': '男', 'company': 'A公司', 'income': 6000}
{'_id': ObjectId('61d70149082b9beb7bca8b1c'), 'name': '李四', 'age': 30, 'sex': '男', 'company': 'B公司', 'income': 5000}
{'_id': ObjectId('61d70149082b9beb7bca8b1d'), 'name': '小红', 'age': 25, 'sex': '女', 'company': 'A公司', 'income': 5500}
{'_id': ObjectId('61d70149082b9beb7bca8b1e'), 'name': '王二', 'age': 26, 'sex': '男', 'company': 'A公司', 'income': 9000}
{'_id': ObjectId('61d70149082b9beb7bca8b1f'), 'name': '小芳', 'age': 26, 'sex': '女', 'company': 'B公司', 'income': 7000}

## 1、分组计数 '$sum':1
grp = {'$group': {'_id':'$sex', 'cnt':{'$sum':1}}}
for i in client['study']['employee'].aggregate([grp]): #注意参数为列表
    print(i)

{'_id': '男', 'cnt': 3}
{'_id': '女', 'cnt': 2}

## 2、分组最值 $max、$min
grp = {'$group': {'_id':'$sex', 'max_income':{'$max':'$income'}, 'min_income':{'$min':'$income'}}} #男女均龄
for i in client['study']['employee'].aggregate([grp]): #注意参数为列表
    print(i)

{'_id': '男', 'max_income': 9000, 'min_income': 5000}
{'_id': '女', 'max_income': 7000, 'min_income': 5500}

## 3、分组平均$avg、求和$sum
grp = {'$group': {'_id':'$sex', 'sum_income':{'$sum':'$income'}, 'avg_income':{'$avg':'$income'}}} 
for i in client['study']['employee'].aggregate([grp]): #注意参数为列表
    print(i)

{'_id': '男', 'sum_income': 20000, 'avg_income': 6666.666666666667}
{'_id': '女', 'sum_income': 12500, 'avg_income': 6250.0}

for i in client['study']['employee'].find({}).sort('income', 1):
    print(i)

{'_id': ObjectId('61d70149082b9beb7bca8b1c'), 'name': '李四', 'age': 30, 'sex': '男', 'company': 'B公司', 'income': 5000}
{'_id': ObjectId('61d70149082b9beb7bca8b1d'), 'name': '小红', 'age': 25, 'sex': '女', 'company': 'A公司', 'income': 5500}
{'_id': ObjectId('61d70149082b9beb7bca8b1b'), 'name': '张三', 'age': 26, 'sex': '男', 'company': 'A公司', 'income': 6000}
{'_id': ObjectId('61d70149082b9beb7bca8b1f'), 'name': '小芳', 'age': 26, 'sex': '女', 'company': 'B公司', 'income': 7000}
{'_id': ObjectId('61d70149082b9beb7bca8b1e'), 'name': '王二', 'age': 26, 'sex': '男', 'company': 'A公司', 'income': 9000}

## 4、最前$first、最后$last：分组排序取其最，类似窗口函数
srt = {'$sort':{'income':1}}
grp = {'$group': {'_id':'$sex', 'first_income':{'$first':'$income'}, 'last_income':{'$last':'$income'}}} 
for i in client['study']['employee'].aggregate([srt,grp]): #注意参数为列表
    print(i)

{'_id': '男', 'first_income': 5000, 'last_income': 9000}
{'_id': '女', 'first_income': 5500, 'last_income': 7000}

## 5、条件+分组
mach = {'$match': {'age':{'$gt':25}}} #年龄>25
grp = {'$group': {'_id':'$sex', 'cnt':{'$sum':1}}}
for i in client['study']['employee'].aggregate([mach, grp]): #注意参数为列表
    print(i)

{'_id': '男', 'cnt': 3}
{'_id': '女', 'cnt': 1}

## 6、多字段分组
grps = {'$group': {'_id':{'公司':'$company','性别':'$sex'}, '最高工资':{'$max':'$income'}}}
for i in client['study']['employee'].aggregate([grps]): #注意参数为列表
    print(i)

{'_id': {'公司': 'A公司', '性别': '男'}, '最高工资': 9000}
{'_id': {'公司': 'B公司', '性别': '女'}, '最高工资': 7000}
{'_id': {'公司': 'A公司', '性别': '女'}, '最高工资': 5500}
{'_id': {'公司': 'B公司', '性别': '男'}, '最高工资': 5000}

## 7、分组汇集列表
#去重 $addToSet
grp1 = {'$group': {'_id':'$company', 'list_sex':{'$addToSet':'$sex'}}}
for i in client['study']['employee'].aggregate([grp1]): #注意参数为列表
    print(i)
    
print('= ' * 50)    
#不去重 $push
grp2 = {'$group': {'_id':'$company', 'list_sex':{'$push':'$sex'}}}
for i in client['study']['employee'].aggregate([grp2]): #注意参数为列表
    print(i)

{'_id': 'B公司', 'list_sex': ['男', '女']}
{'_id': 'A公司', 'list_sex': ['男', '女']}
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
{'_id': 'B公司', 'list_sex': ['男', '女']}
{'_id': 'A公司', 'list_sex': ['男', '女', '男']}

## 仅查看文档数可用 count_documents()
client['study']['employee'].count_documents({})

5

六、索引

## 创建索引
client['study']['mongo_study_sites'].create_index([('desc', pymongo.ASCENDING)], unique=True) # 唯一索引，可防止重复数据

# 查看索引信息
print(list(client['study']['mongo_study_sites'].index_information()))  #'_id'是默认的索引

# 尝试插入一条重复数据
doc = {'desc': 'MongoDB菜鸟教程'}
try:
    client['study']['mongo_study_sites'].insert_one(doc)
except Exception as e: #查看错误
    print(str(e))

['_id_', 'desc_1']
E11000 duplicate key error collection: study.mongo_study_sites index: desc_1 dup key: { desc: "MongoDB菜鸟教程" }, full error: {'index': 0, 'code': 11000, 'keyPattern': {'desc': 1}, 'keyValue': {'desc': 'MongoDB菜鸟教程'}, 'errmsg': 'E11000 duplicate key error collection: study.mongo_study_sites index: desc_1 dup key: { desc: "MongoDB菜鸟教程" }'}

标签：教程,num,管理,MongoDB,study,client,pymongo,id,desc
From： https://www.cnblogs.com/unique2cxy/p/16704888.html