2018年7月6日笔记 下文中的操作都是使用python操作mongoDB，所以前提是必须安装python和mongoDB。
1. 安装pymongo
在cmd或者PowerShell中运行命令:pip install pymongo
2. 插入数据
2.1 插入一条数据
引入pymongo库中的MongoClient类，使用该类的初始化方法实例化一个对象赋值给conn conn.myschool为数据库school，将其赋值给变量db db.students为数据库school中的students集合，将其赋值给变量students 定义一个数据类型为字典dict的变量zhangsan 往数据库中的students集合中插入zhangsan的信息文档，students.insert_one(zhangsan)
代码语言：javascript复制from pymongo import MongoClient
if __name__ == '__main__':
conn = MongoClient('localhost')
db = conn.myschool
students = db.students
zhangsan = dict(
name="zhangsan",
age=20,
sex="boy",
contact=dict(
email1="abc@qq.com",
email2="123@qq.com"
)
)
students.insert_one(zhangsan)2.2 插入多条数据
代码语言：javascript复制from pymongo import MongoClient
if __name__ == '__main__':
conn = MongoClient('localhost')
db = conn.myschool
students = db.students
lisi = dict(
name = 'lisi',
habit = dict(
habit1 = 'eat',
habit2 = 'sleep'
)
)
wangwu = dict(
name = 'wangwu',
age = 20,
sex = 'boy'
)
students.insert_many([lisi,wangwu])2.3 使用循环创建3个班，并随机添加10个学生
代码语言：javascript复制from pymongo import MongoClient
from random import randint
if __name__ == '__main__':
conn = MongoClient('localhost')
db = conn.school
hobby_list = ['sing','drawing','run','football','basketball']
grade_list = ['grade_1_1','grade_1_2','grade_1_3']
for grade in grade_list:
collection = db.get_collection(grade)
collection.drop()
for i in range(10):
student = dict(
name = "zhangsan" str(i),
age = randint(1,9),
sex = "男" if randint(0,1) else "女",
hobby = hobby_list[:randint(0,5)]
)
collection.insert_one(student)3.查询数据
在进行查询的时候，必须要先执行2-3节中的代码，确保school数据库中插入3个班集合
3.1 查询集合中全部数据
示例代码如下：
代码语言：javascript复制from pymongo import MongoClient
if __name__ == '__main__':
conn = MongoClient('localhost')
db = conn.school
students = db.grade_1_3
cursor = students.find()
for i in cursor:
print(i)
图片.png-57.9kB
3.2 过滤查询
查询之前先定义一个数据类型为字典dict的变量filter filter示例,查询年龄等于4的文档：filter = {"age":4} 代码示例如下，代码能够成功运行，具体的数据库名和集合名要根据自己电脑中的MongoDB情况进行更改：
代码语言：javascript复制from pymongo import MongoClient
if __name__ == '__main__':
conn = MongoClient('localhost')
db = conn.school
students = db.grade_1_3
filter = {"age": 4}
cursor = students.find(filter)
for i in cursor:
print(i)filter中操作符及其含义
图片.png-131.5kB
3.2.1 $in操作符示例：
代码语言：javascript复制from pymongo import MongoClient
if __name__ == '__main__':
conn = MongoClient('localhost')
db = conn.school
students = db.grade_1_3
filter = {"name": {'$in':['zhangsan2','zhangsan3']}}
cursor = students.find(filter)
for i in cursor:
print(i)上面一段代码的运行结果如下：
{'_id': ObjectId('5b3f0ea2ba50f64850ef1cda'), 'name': 'zhangsan2', 'age': 3, 'sex': '女', 'hobby': ['sing', 'drawing']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cdb'), 'name': 'zhangsan3', 'age': 3, 'sex': '男', 'hobby': ['sing', 'drawing', 'run', 'football']}
3.2.2 $gt操作符示例：
代码语言：javascript复制from pymongo import MongoClient
if __name__ == '__main__':
conn = MongoClient('localhost')
db = conn.school
students = db.grade_1_3
filter = {"age": {'$gt':4}}
cursor = students.find(filter)
for i in cursor:
print(i)上面一段代码的运行结果如下:
{'_id': ObjectId('5b3f0ea2ba50f64850ef1cd8'), 'name': 'zhangsan0', 'age': 7, 'sex': '女', 'hobby': ['sing', 'drawing', 'run']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cd9'), 'name': 'zhangsan1', 'age': 5, 'sex': '女', 'hobby': ['sing', 'drawing', 'run', 'football']}
3.2.3 $gte操作符示例:
代码语言：javascript复制from pymongo import MongoClient
if __name__ == '__main__':
conn = MongoClient('localhost')
db = conn.school
students = db.grade_1_3
filter = {"age": {'$gte':4}}
cursor = students.find(filter)
for i in cursor:
print(i)上面一段代码运行结果如下：
{'_id': ObjectId('5b3f0ea2ba50f64850ef1cd8'), 'name': 'zhangsan0', 'age': 7, 'sex': '女', 'hobby': ['sing', 'drawing', 'run']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cd9'), 'name': 'zhangsan1', 'age': 5, 'sex': '女', 'hobby': ['sing', 'drawing', 'run', 'football']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cdc'), 'name': 'zhangsan4', 'age': 4, 'sex': '女', 'hobby': ['sing', 'drawing', 'run']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cdf'), 'name': 'zhangsan7', 'age': 4, 'sex': '女', 'hobby': ['sing', 'drawing']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1ce1'), 'name': 'zhangsan9', 'age': 4, 'sex': '女', 'hobby': ['sing', 'drawing', 'run']}
4.更新数据
4.1使用update_many函数
让所有文档中的sex字段都被修改为“男”。
代码语言：javascript复制from pymongo import MongoClient
if __name__ == '__main__':
conn = MongoClient('localhost')
db = conn.school
students = db.grade_1_3
filter = {"sex":"女"}
updater = {"$set":{"sex":"男"}}
students.update_many(filter,updater)
cursor = students.find()
for i in cursor:
print(i)上面一段代码的运行结果如下：
{'_id': ObjectId('5b3f0ea2ba50f64850ef1cd8'), 'name': 'zhangsan0', 'age': 7, 'sex': '男', 'hobby': ['sing', 'drawing', 'run']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cd9'), 'name': 'zhangsan1', 'age': 5, 'sex': '男', 'hobby': ['sing', 'drawing', 'run', 'football']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cda'), 'name': 'zhangsan2', 'age': 3, 'sex': '男', 'hobby': ['sing', 'drawing']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cdb'), 'name': 'zhangsan3', 'age': 3, 'sex': '男', 'hobby': ['sing', 'drawing', 'run', 'football']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cdc'), 'name': 'zhangsan4', 'age': 4, 'sex': '男', 'hobby': ['sing', 'drawing', 'run']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cdd'), 'name': 'zhangsan5', 'age': 1, 'sex': '男', 'hobby': ['sing', 'drawing', 'run', 'football']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cde'), 'name': 'zhangsan6', 'age': 2, 'sex': '男', 'hobby': ['sing']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1cdf'), 'name': 'zhangsan7', 'age': 4, 'sex': '男', 'hobby': ['sing', 'drawing']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1ce0'), 'name': 'zhangsan8', 'age': 1, 'sex': '男', 'hobby': ['sing', 'drawing']} {'_id': ObjectId('5b3f0ea2ba50f64850ef1ce1'), 'name': 'zhangsan9', 'age': 4, 'sex': '男', 'hobby': ['sing', 'drawing', 'run']}
4.2 $inc操作符示例
让所有文档的age字段加2，即让集合grade_1_1中的所有人年龄加2
代码语言：javascript复制from pymongo import MongoClient
def printMongo(collection,filter={},num=3):
cursor = collection.find(filter)
for i in cursor[:num]:
print(i)
if __name__ == "__main__":
conn = MongoClient("localhost")
db = conn.school
students = db.grade_1_1
printMongo(students)
updater = {"$inc":{"age":2}}
students.update_many({},updater)
print("MongoDB更新数据后：")
printMongo(students)上面一段代码的运行结果如下：
{'_id': ObjectId('5b403bdc33514c04b891a363'), 'name': 'zhangsan0', 'age': 7, 'sex': '男', 'hobby': ['sing', 'drawing', 'run', 'football', 'basketball']} {'_id': ObjectId('5b403bdc33514c04b891a364'), 'name': 'zhangsan1', 'age': 4, 'sex': '男', 'hobby': ['sing', 'drawing', 'run']} {'_id': ObjectId('5b403bdc33514c04b891a365'), 'name': 'zhangsan2', 'age': 7, 'sex': '女', 'hobby': []} MongoDB更新数据后： {'_id': ObjectId('5b403bdc33514c04b891a363'), 'name': 'zhangsan0', 'age': 9, 'sex': '男', 'hobby': ['sing', 'drawing', 'run', 'football', 'basketball']} {'_id': ObjectId('5b403bdc33514c04b891a364'), 'name': 'zhangsan1', 'age': 6, 'sex': '男', 'hobby': ['sing', 'drawing', 'run']} {'_id': ObjectId('5b403bdc33514c04b891a365'), 'name': 'zhangsan2', 'age': 9, 'sex': '女', 'hobby': []}
4.3 $min操作符示例
与当前值进行比较，更新值为两者中的较小值 下面一段代码将所有age字段大于6的文档中的age字段修改为6
代码语言：javascript复制from pymongo import MongoClient
def printMongo(collection,filter={},num=5):
cursor = collection.find(filter)
for i in cursor[:num]:
print(i)
if __name__ == "__main__":
conn = MongoClient("localhost")
db = conn.school
students = db.grade_1_1
printMongo(students)
updater = {"$min":{"age":6}}
students.update_many({},updater)
print("MongoDB更新数据后：")
printMongo(students)上面一段代码的运行结果如下:
{'_id': ObjectId('5b403efd33514c189890748f'), 'name': 'zhangsan0', 'age': 4, 'sex': '男', 'hobby': ['sing', 'drawing', 'run']} {'_id': ObjectId('5b403efe33514c1898907490'), 'name': 'zhangsan1', 'age': 9, 'sex': '男', 'hobby': []} {'_id': ObjectId('5b403efe33514c1898907491'), 'name': 'zhangsan2', 'age': 1, 'sex': '男', 'hobby': ['sing']} {'_id': ObjectId('5b403efe33514c1898907492'), 'name': 'zhangsan3', 'age': 7, 'sex': '女', 'hobby': ['sing', 'drawing', 'run', 'football']} {'_id': ObjectId('5b403efe33514c1898907493'), 'name': 'zhangsan4', 'age': 2, 'sex': '男', 'hobby': ['sing', 'drawing', 'run']} MongoDB更新数据后： {'_id': ObjectId('5b403efd33514c189890748f'), 'name': 'zhangsan0', 'age': 4, 'sex': '男', 'hobby': ['sing', 'drawing', 'run']} {'_id': ObjectId('5b403efe33514c1898907490'), 'name': 'zhangsan1', 'age': 6, 'sex': '男', 'hobby': []} {'_id': ObjectId('5b403efe33514c1898907491'), 'name': 'zhangsan2', 'age': 1, 'sex': '男', 'hobby': ['sing']} {'_id': ObjectId('5b403efe33514c1898907492'), 'name': 'zhangsan3', 'age': 6, 'sex': '女', 'hobby': ['sing', 'drawing', 'run', 'football']} {'_id': ObjectId('5b403efe33514c1898907493'), 'name': 'zhangsan4', 'age': 2, 'sex': '男', 'hobby': ['sing', 'drawing', 'run']}
$currentDate操作符示例
添加的时间是按照0时区时间计时：比如本文作者实验时间为2018年7月7日12时28分（北京时间东8区），下面一段代码执行时记录的时间是2018年7月7日4时28分。
代码语言：javascript复制from pymongo import MongoClient
def printMongo(collection,filter={},num=2):
cursor = collection.find(filter)
for i in cursor[:num]:
print(i)
if __name__ == "__main__":
conn = MongoClient("localhost")
db = conn.school
students = db.grade_1_1
printMongo(students)
updater = {"$currentDate":{"create_time":True}}
students.update_many({},updater)
print("MongoDB更新数据后：")
printMongo(students)上面一段代码的运行结果如下:
{'_id': ObjectId('5b40413a33514c36d8a854ee'), 'name': 'zhangsan0', 'age': 8, 'sex': '女', 'hobby': ['sing', 'drawing']} {'_id': ObjectId('5b40413a33514c36d8a854ef'), 'name': 'zhangsan1', 'age': 5, 'sex': '男', 'hobby': ['sing', 'drawing', 'run', 'football']} MongoDB更新数据后： {'_id': ObjectId('5b40413a33514c36d8a854ee'), 'name': 'zhangsan0', 'age': 8, 'sex': '女', 'hobby': ['sing', 'drawing'], 'create_time': datetime.datetime(2018, 7, 7, 4, 28, 0, 527000)} {'_id': ObjectId('5b40413a33514c36d8a854ef'), 'name': 'zhangsan1', 'age': 5, 'sex': '男', 'hobby': ['sing', 'drawing', 'run', 'football'], 'create_time': datetime.datetime(2018, 7, 7, 4, 28, 0, 527000)}
5.删除数据
delete_many()函数用于删除多条数据 delete_one()函数用于删除一条数据
6.查询同时更新
三个可以利用来操作满足filter筛选条件的第一条文档的函数: find_one_and_replace() find_one_and_delete() find_one_and_update()
作业
新建mongoDB数据库employee,里面有两个集合employee_info、employee_salary (1)分别添加2个集合的数据 (2)查询employee_salary工资大于2000的；查询employee_info员工名称=xxx) (3)修改employee_salary集合(将员工工资增加3000） (4)删除员工aa的信息
4道小题合在一起的代码如下:
代码语言：javascript复制from pymongo import MongoClient
def printMongo(collection,filter={},num=2):
cursor = collection.find(filter)
for i in cursor[:num]:
print(i)
if __name__ == "__main__":
conn = MongoClient("localhost")
db = conn.employee
info = db.employee_info
salary = db.employee_salary
#第1小题
info.drop()
salary.drop()
info.insert_one({"name":"aa","sex":"男","age":23})
info.insert_one({"name":"bb","sex":"女","age":20})
salary.insert_one({"name":"aa","salary":3000})
salary.insert_one({"name": "bb", "salary": 1800})
printMongo(info)
printMongo(salary)
# 第2小题
filter = {"salary":{"$gt":2000}}
print("找出工资大于2000的员工：")
printMongo(salary,filter)
filter2 = {'name':"bb"}
print("找出姓名为bb的员工")
printMongo(info,filter2)
##第3小题
print("没有增加工资时：")
printMongo(salary)
updater = {"$inc":{"salary":3000}}
salary.update_many({},updater)
print("增加工资后：")
printMongo(salary)
##第4小题
print("没有删除员工aa时打印所有员工信息:")
printMongo(info)
printMongo(salary)
print("删除员工aa后打印所有员工信息")
info.delete_one({"name":"aa"})
salary.delete_one({"name":"aa"})
printMongo(info)
printMongo(salary)上面一段代码的运行结果如下：
{'_id': ObjectId('5b404b3333514c1dd0f6c096'), 'name': 'aa', 'sex': '男', 'age': 23} {'_id': ObjectId('5b404b3333514c1dd0f6c097'), 'name': 'bb', 'sex': '女', 'age': 20} {'_id': ObjectId('5b404b3333514c1dd0f6c098'), 'name': 'aa', 'salary': 3000} {'_id': ObjectId('5b404b3333514c1dd0f6c099'), 'name': 'bb', 'salary': 1800} 找出工资大于2000的员工： {'_id': ObjectId('5b404b3333514c1dd0f6c098'), 'name': 'aa', 'salary': 3000} 找出姓名为bb的员工 {'_id': ObjectId('5b404b3333514c1dd0f6c097'), 'name': 'bb', 'sex': '女', 'age': 20} 没有增加工资时： {'_id': ObjectId('5b404b3333514c1dd0f6c098'), 'name': 'aa', 'salary': 3000} {'_id': ObjectId('5b404b3333514c1dd0f6c099'), 'name': 'bb', 'salary': 1800} 增加工资后： {'_id': ObjectId('5b404b3333514c1dd0f6c098'), 'name': 'aa', 'salary': 6000} {'_id': ObjectId('5b404b3333514c1dd0f6c099'), 'name': 'bb', 'salary': 4800} 没有删除员工aa时打印所有员工信息: {'_id': ObjectId('5b404b3333514c1dd0f6c096'), 'name': 'aa', 'sex': '男', 'age': 23} {'_id': ObjectId('5b404b3333514c1dd0f6c097'), 'name': 'bb', 'sex': '女', 'age': 20} {'_id': ObjectId('5b404b3333514c1dd0f6c098'), 'name': 'aa', 'salary': 6000} {'_id': ObjectId('5b404b3333514c1dd0f6c099'), 'name': 'bb', 'salary': 4800} 删除员工aa后打印所有员工信息 {'_id': ObjectId('5b404b3333514c1dd0f6c097'), 'name': 'bb', 'sex': '女', 'age': 20} {'_id': ObjectId('5b404b3333514c1dd0f6c099'), 'name': 'bb', 'salary': 4800}
