Python MongoDB
依靠pymongo包来对mongoDB数据库进行操作
一、pymongo安装
首先通过pip list或者通过import pymongo,查看自己装没装pymongo。
pip install pymongo
出错提示版本匹配有问题。
通过Anaconda中安装pymongo环境,失败。
重新更新pip版本
python -m pip install --upgrade pip
更新成功后,再pip install pymongo,成功!!
二、pymongo基本操作
1.创建数据库
连接名["库名"]
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
#创建名字为runoob的数据库
mydb = myclient["runoob"]
2.获取数据库列表
连接名.list_database_names()
import pymongo
myclient = pymongo.MongoClient('mongodb://localhost:27017/')
#获取数据库列表
dblist = myclient.list_database_names()
if "runoobdb" in dblist:
print("数据库已存在!")
3.创建集合(表)
库名["集合名"]
import pymongo
myclient = pymongo.MongoClient('mongodb://localhost:27017/')
mydb = myclient["runoob"]
#创建名字为sites的集合
mycol = mydb["sites"]
4.获取集合列表
库名.list_collection_names()
import pymongo
myclient = pymongo.MongoClient('mongodb://localhost:27017/')
mydb = myclient['runoobdb']
#获取集合列表
collist = mydb.list_collection_names()
if "sites" in collist: # 判断 sites 集合是否存在
print("集合已存在!")
5.插入文档
5.1 插入单个文档
集合名.inset_one()
该方法返回 InsertOneResult 对象,该对象包含 inserted_id 属性,它是插入文档的 id 值。
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
mydict = {"name":"RUNOOB","alexa":"10000","url":"https://www.runoob.com"}
x = mycol.insert_one(mydict)
print(x)
print(x.inserted_id)
5.2 插入多个文档
集合名.inset_many()
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
mylist = [
{ "name": "Taobao", "alexa": "100", "url": "https://www.taobao.com" },
{ "name": "QQ", "alexa": "101", "url": "https://www.qq.com" },
{ "name": "Facebook", "alexa": "10", "url": "https://www.facebook.com" },
{ "name": "知乎", "alexa": "103", "url": "https://www.zhihu.com" },
{ "name": "Github", "alexa": "109", "url": "https://www.github.com" }
]
x = mycol.insert_many(mylist)
# 输出插入的所有文档对应的 _id 值
print(x.inserted_ids)
5.2 插入多个文档(指定_id)
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["site2"]
mylist = [
{ "_id": 1, "name": "RUNOOB", "cn_name": "菜鸟教程"},
{ "_id": 2, "name": "Google", "address": "Google 搜索"},
{ "_id": 3, "name": "Facebook", "address": "脸书"},
{ "_id": 4, "name": "Taobao", "address": "淘宝"},
{ "_id": 5, "name": "Zhihu", "address": "知乎"}
]
x = mycol.insert_many(mylist)
# 输出插入的所有文档对应的 _id 值
print(x.inserted_ids)
6.查询文档
6.1 查询单个文档
集合名.find_one()
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
x = mycol.find_one()#无条件,即为第一条数据
print(x)
6.2 查询所有文档
集合名.find()
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017")
mydb = myclient["runoob"]
mycol = mydb["sites"]
for x in mycol.find()
print(x)
for y in mycol.find({},{"_id":0,"title":1})
print(y)
除了 _id ,你不能在一个对象中同时指定 0 和 1(如{ “name”: 1, “alexa”: 0 }),如果你设置了一个字段为 0,则其他都为 1,反之亦然。
6.3 查询指定条件文档
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
#查询名字为RUNOOB的文档
myquery = { "name": "RUNOOB" }
mydoc = mycol.find(myquery)
for x in mydoc:
print(x)
6.4 高级查询
基本和mongoDB中写法相同。
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
myquery = { "name": { "$gt": "H" } }
mydoc = mycol.find(myquery)
for x in mydoc:
print(x)
6.5 使用正则表达式匹配字符串
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
#"$regex"表示使用正则表达式,"^R"表示首字母为R
myquery = { "name": { "$regex": "^R" } }
mydoc = mycol.find(myquery)
for x in mydoc:
print(x)
6.6 返回指定记录数
集合名.find().limit(num)
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
myresult = mycol.find().limit(3)
# 输出结果
for x in myresult:
print(x)
7.修改文档
7.1 修改单个文档
集合名.update_one()
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
myquery = { "alexa": "10000" }
newvalues = { "$set": { "alexa": "12345" } }
mycol.update_one(myquery, newvalues)
# 输出修改后的 "sites" 集合
for x in mycol.find():
print(x)
7.1 修改多个文档
集合名.update_many()
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
myquery = { "alexa": { "$reget":"^F"} }
newvalues = { "$set": { "alexa": "123" } }
x = mycol.update_many(myquery, newvalues)
# 输出修改匹配的数量
print(x.modified_count, "文档已修改")
8.排序文档
集合名.find().sort()
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
#"-1"为降序排列
mydoc = mycol.find().sort("alexa",-1)
for x in mydoc:
print(x)
9.删除数据
9.1 删除单个文档
集合名.delete_one()
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
myquery = { "name": "Taobao" }
mycol.delete_one(myquery)
# 删除后输出
for x in mycol.find():
print(x)
9.2 删除多个文档
集合名.delete_many()
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
myquery = { "name": {"$reget":"^F"} }
x = mycol.delete_many(myquery)
# 删除后输出
print(x.deleted_count, "个文档已删除")
9.3 删除所有文档
集合名.delete_many()
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
#传入空的查询对象
x = mycol.delete_many({})
# 删除后输出
print(x.deleted_count, "个文档已删除")
9.4 删除集合
集合名.drop()
import pymongo
myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["runoobdb"]
mycol = mydb["sites"]
mycol.drop()