mongdb入门案例

实验一 新建mogodb的库

import pymongo
from pymongo import MongoClient
# client=MongoClient("localhost",27017) #和下面一行二选一
client = MongoClient("mongodb://localhost:27017/")
for i in range(2,30):#操作数据库
    db=client["ccf1"]#新建集合
    db["ccf23"].insert({"KEasYS":2874435})#集合中建立关系表
dblist = client.list_database_names()#数据集合名字
if "ccf1" in dblist:
  print("数据库已存在！")
client.close

---

实验二 插入集合
2.1插入一个数据

#!/usr/bin/python3
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
mydict = { "name": "WV", "AREA": "嘉定"}#支持中文
x = mycol.insert_one(mydict) #返回这个数据的id，id是全局唯一变量
print(x)

2.2插入多个数据

#!/usr/bin/python3 
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
mylist = [
    { "name": "WV", "AREA": "中国"},
    { "name": "WV", "AREA": "SH"},
    { "name": "WV", "AREA": "安亭"},
    { "_id":"12345","name": "WV", "AREA": "待定","投资":"1000W"}#指定id，可以是字符串也可以是数字；存储的数据可以结构不一样
]
x = mycol.insert_many(mylist)
print(x.inserted_ids)

---

实验三 数据检索
3.1检索单个数据

#!/usr/bin/python3 
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
mylist = [
    { "name": "WV", "AREA": "中国"},
    { "name": "WV", "AREA": "SH"},
    { "name": "WV", "AREA": "安亭"},
    { "name": "WV","part":"荣威 RX5", "AREA": "待定","投资":"1000W"}
]
x = mycol.insert_many(mylist)
print(x.inserted_ids)
print(mycol.find_one())#本数据库的第一个数据

3.2检索所有数据

#!/usr/bin/python3 
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
mylist = [
    { "name": "WV", "AREA": "中国"},
    { "name": "WV", "AREA": "SH"},
    { "name": "WV", "AREA": "安亭"},
    { "name": "WV","part":"荣威 RX5", "AREA": "待定","投资":"1000W"}
]
x = mycol.insert_many(mylist)
print(x.inserted_ids)
for i in mycol.find():#打出所有数据
  print(i)
  print(i["name"])#用关键字打出对应的键值

3.3检索指定字段的数据

#!/usr/bin/python3 
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
mylist = [
    { "name": "WV", "AREA": "中国"},
    { "name": "WV", "AREA": "SH"},
    { "name": "WV", "AREA": "安亭"},
    { "name": "WVg","part":"荣威 W5", "AREA": "待定","投资":"1000W"}
]
x = mycol.insert_many(mylist)
for x in mycol.find({"part":{"$regex": "R"}}):#加入正则表达式
  print(x)

for x in mycol.find({"part":"荣威"}):#加入限定条件，只要part中包括荣威就会被列出
  print(x)

for x in mycol.find({},{ "_id": 0, "part": 1, "投资": 1 }):#检测关键字存在
  print(x)

myresult = mycol.find().limit(3)#反馈前三条
for x in myresult:
    print(x)

---

实验四 改数据
4.1修改所有匹配到的记录

#!/usr/bin/python3 
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
myquery = { "name": "WV","part":"荣威 RX5" }#检索筛选条件
newvalues = { "$set": { "AREA": "嘉定" } }#替换的数据
x = mycol.update_many(myquery, newvalues)#替换触发

4.2修改单条记录

#!/usr/bin/python3 
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
myquery = { "name": "WV","part":"荣威 RX5" }#检索筛选条件
newvalues = { "$set": { "AREA": "扬州" } }#替换的数据
mycol.update_one(myquery, newvalues)#替换触发，只修改遇到的第一条数据
# 输出修改后的  "sites"  集合
for x in mycol.find():
  print(x)

---

实验五 排序
5.1

#!/usr/bin/python3 
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
mydoc = mycol.find().sort("part",-1)#按照part的值倒叙排序，值相同的比较_id
for x in mydoc:
  print(x)

---

实验六 删除数据
6.1删除单个字段

#!/usr/bin/python3 
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
myquery = { "AREA": "anting" }
mycol.delete_one(myquery)
for x in mycol.find():
  print(x)

6.2删除所有字段

#!/usr/bin/python3 
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
myquery = { "AREA": "anting" }
mycol.delete_many(myquery)
for x in mycol.find():
  print(x)

6.3删除集合

#!/usr/bin/python3 
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["saic"]
mycol = mydb["sites"]
mycol.drop()

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