MySQL学习笔记05（redis，mongoDB）

一、python远程操作 redis

1.1 前提准备

1、安装redis第三方库

pip install redis

2、修改配置文件

vim redis.conf

注释掉/bind中：bind 127.0.0.1 (ip)

修改/protected：protected-mode no (关闭安全模式)

1、创建一个产品表
mysql -h localhost -u root -p
use mydb;
create table products(
id   int primary key auto_increment,
name  varchar(20) not null,
price  double  not null
);
#插入记录
insert into products(name,price)values('洗衣粉',12.5),('旺旺雪饼',15),('辣条',5);
#查看表
select * from products;
+----+--------------+-------+
| id | name         | price |
+----+--------------+-------+
|  1 | 洗衣粉       |  12.5 |
|  2 | 旺旺雪饼     |    15 |
|  3 | 辣条         |     5 |
+----+--------------+-------+
2、启动redis
ywh@ywh:~$ redis-server redis.conf
ywh@ywh:~$ redis-cli
127.0.0.1:6379> 

1.2 python代码演示

# cache_tool.py
import pymysql,redis
​
def selectFromMySQL(_id):  # 根据产品id从MySQL数据库查询产品
    conn = pymysql.Connect(
        host='192.168.0.111:22',#虚拟机地址
        port=3306,
        user='root',
        password='rock1204',
        database='mydb',
        charset='utf8',
    )
    cursor = conn.cursor()
    sql = "select id,name,price from products where id=%d"
    try:
        cursor.execute(sql%_id)
        product = cursor.fetchone()
    except Exception as e:
        print("操作MySQL查询数据发生异常了：",e)
    finally:
        cursor.close()
        conn.close()
    return product
​
def saveToRedis(product):   # 将MySQL中查询的产品保存到Redis中
    r = redis.Redis("192.168.0.111:22",6379)  # 创建操作Redis的实例
    r.hmset("product:"+str(product[0]),{'id':product[0],'name':product[1],'price':product[2]})
​
def selectFromRedis(_id):  # 从Redis中查询数据，并返回
    r = redis.Redis("192.168.0.111:22", 6379)  # 创建操作Redis的实例
    product_dict = r.hgetall("product:"+str(_id)) # 以字典形式获取,字节序列
    show_result = {}
    for k,v in product_dict.items():
        show_result[k.decode()] = v.decode()  # 解码字节序列
​
    return show_result

#client.py
from cache_tool import *
​
_id = 1
print("先从Redis中查询")
data = selectFromRedis(_id)  # 从Redis中查
print("从Redis中查询的数据是：",data)
if data:
    print("恭喜，Redis命中啦~~~")
    print("从Redis中查询的数据是：",data)
else:
    print("Redis中没有，只能从MySQL中查询了。。。。。。")
    product = selectFromMySQL(_id)
    if product:
        saveToRedis(product)
        print('已经将产品信息保存到Redis了')
        print("从MySQL中查询的信息是：",product)
    else:
        print("Sorry,系统暂无此信息!!!")
​

二、mangoDB

查看镜像来源

vim /etc/apt/sources.list

vim /etc/apt/sources.list
​
# deb cdrom:[Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)]/ xenial main restricted
​
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://mirrors.aliyun.com/ubuntu/ xenial main restricted
# deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial main restricted
​
## Major bug fix updates produced after the final release of the
## distribution.
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted
# deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial-updates main restricted
​
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://mirrors.aliyun.com/ubuntu/ xenial universe
# deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
# deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial-updates universe
​
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://mirrors.aliyun.com/ubuntu/ xenial multiverse
# deb-src http://cn.archive.ubuntu.com/ubuntu/ xenial multiverse
"/etc/apt/sources.list" [只读] 51L, 2885C   

2.1 MongoDB简介

MongoDB 是由C++语言编写的，是一个基于分布式文件存储的开源数据库管理系统

安装方式：

sudo apt-get install mongodb

进入mongodb环境：mongo

数据库(db)------>集合(collections)---->文档

2.2 MongoDB的操作

查看所有数据库 : show dbs

查看当前数据库: db

进入指定数据库: use 数据库名

显示当前库中所有的集合: show collections

创建一个集合: db.createCollection("集合名称”)

向集合中插入文档:

db.集合称.insert({name:'tom',age:20,score:65})

db.集合名称.save(数据) # 若存在，则修改

查询指定集合的所有数据

db.集合名称.find()

db.集合名称.find().pretty()

删除集合

db.集合名.drop()

删除当前数据库

db.dropDatabase()

例一:查询students集合中成绩大于80分的文档

db.students.find({score:{$gt:80}})

例二：查询students集合中成绩大于80分且小于90分的文档

db.students.find({score:{​lt:90}})

例三：从students集合中删除名字为‘alice’的文 档

db.students.remove({name:'alice'})

2.3 代码演示

ywh@ywh:~$ mongo  #进入mongoDB
MongoDB shell version: 2.6.10
connecting to: test
> db    #查看当前数据库
test
> show dbs   #查看所有数据库  
admin  (empty)
local  0.078GB
> db #查看当前数据库
test
> use mydb    #进入指定数据库
switched to db mydb
> show collections   #查看所有集合
> db    #查看当前数据库
mydb
> show dbs     #查看所有数据库 
admin  (empty)
local  0.078GB
mydb   (empty)
> db.createCollection('students')  #创建students集合
{ "ok" : 1 }
> show collections    #查看所有集合
students
system.indexes
> db.students.insert({name:'tom',age:20,score:83.5})   #向students集合中插入文档
WriteResult({ "nInserted" : 1 })
> db.students.save({name:'jerry',age:28,score:63.5,sex:'man'}) #向students集合中插入文档，save：如果存在该文档则表示修改
WriteResult({ "nInserted" : 1 })
> db.students.find()  #查看数据库所有文档
{ "_id" : ObjectId("5bb329c0a9f09b8ba5efd5f1"), "name" : "tom", "age" : 20, "score" : 83.5 }
{ "_id" : ObjectId("5bb32a86a9f09b8ba5efd5f2"), "name" : "jerry", "age" : 28, "score" : 63.5, "sex" : "man" }
> db.students.find().pretty()     #查看数据库所有文档并格式化
{
    "_id" : ObjectId("5bb329c0a9f09b8ba5efd5f1"),
    "name" : "tom",
    "age" : 20,
    "score" : 83.5
}
{
    "_id" : ObjectId("5bb32a86a9f09b8ba5efd5f2"),
    "name" : "jerry",
    "age" : 28,
    "score" : 63.5,
    "sex" : "man"
}
> db.students.find({score:{$gt:80}}) #查询students集合中成绩大于80分的文档
 { "_id" : ObjectId("5bb329c0a9f09b8ba5efd5f1"), "name" : "tom", "age" : 20, "score" : 83.5 }
> db.students.find({score:{$gt:60,$lt:80}})  查询students集合中成绩大于60分且小于80分的文档
{ "_id" : ObjectId("5bb32a86a9f09b8ba5efd5f2"), "name" : "jerry", "age" : 28, "score" : 63.5, "sex" : "man" }
> db.students.remove({name:'jerry'})  #删除文档
WriteResult({ "nRemoved" : 1 })
> db.students.save({name:'jerry',age:28,score:63.5,sex:'man'})
WriteResult({ "nInserted" : 1 })
> db.students.find().sort({score:1})   #升序排序
{ "_id" : ObjectId("5bb32e60a9f09b8ba5efd5f3"), "name" : "jerry", "age" : 28, "score" : 63.5, "sex" : "man" }
{ "_id" : ObjectId("5bb329c0a9f09b8ba5efd5f1"), "name" : "tom", "age" : 20, "score" : 83.5 }
> db.students.find().sort({score:-1})  #降序排序
{ "_id" : ObjectId("5bb329c0a9f09b8ba5efd5f1"), "name" : "tom", "age" : 20, "score" : 83.5 }
{ "_id" : ObjectId("5bb32e60a9f09b8ba5efd5f3"), "name" : "jerry", "age" : 28, "score" : 63.5, "sex" : "man" }
> db.students.drop()   #删除集合
true
> show dbs
admin  (empty)
local  0.078GB
mydb   0.078GB
> db.dropDatabase()    #删除数据库
{ "dropped" : "mydb", "ok" : 1 }
> show dbs
admin  (empty)
local  0.078GB