数据库学习笔记04- redis
5, Redis 基础
redis -- KV 数据库 -- 内存 -- 单线程+异步i/o (多路io复用)
计算密集型应用：多进程+多进程
IO密集型应用：单线程+异步IO(协程)
2008年 -- redis --》 REmote DIctionary Service
冷数据（不经常使用）/ 热数据（经常使用）
- 高速缓存服务（用户经常访问的内容从数据库搬到内存）
- 实时排行榜
- 投票点赞
- 消息队列
redis 命令集： http://redisdoc.com/
安装redis
#1,下载redis到data目录，可以指定版本
wget https://download.redis.io/releases/redis-6.2.7.tar.gz
#2，解压缩redis
tar -xzvf redis-6.2.7.tar.gz
#3，将redis文件移动到local目录
mv redis-6.2.7 /usr/local/redis
#4，安装redis依赖gcc，如果之前已经安装，可省略这一步
yum install gcc -y
#5，编译安装redis,默认安装路径为/usr/local/bin目录
cd /usr/local/redis/
make && make install
#6,启动redis服务器端，推荐后台启动
redis-server ./redis.conf > redis.log &
redis-server --port 6379 --requirepass 1qaz2wsx --appendonly yes
#或者
# 打开redis命令:
service redis start
#启动redis客户端
redis-cli -h hostIP -p port
# 关闭redis命令:
service redis stop
#7,查看redis进程
jobs
[1]+ 运行中 redis-server > redis.log &
#8,关闭redis
redis-cli shutdown
[1]+ 完成 redis-server > redis.log
redis基本操作
#进入本机redis
redis-cli
#进入远程redis
redis-cli -h hostname/ip
#测试连接
127.0.0.1:6379> ping
PONG
#写数据
127.0.0.1:6379> set username forrest
OK
#读数据
127.0.0.1:6379> get username
"forrest"
#写数据加过期时间
127.0.0.1:6379> set 18911112222 423567 ex 300
OK
127.0.0.1:6379> ttl 18911112222
#退出redis客户端
127.0.0.1:6379> quit
#测试redis性能，自动执行
redis-benchmark
#基本操作命令
[root@node1 redis]# redis-cli
#查看键值
127.0.0.1:6379> keys *
1) "mylist"
2) "username"
3) "key:__rand_int__"
4) "myhash"
5) "counter:__rand_int__"
#查看键的类型
127.0.0.1:6379> type username
string
#选择数据库，默认建16个数据库
127.0.0.1:6379> select 1
OK
127.0.0.1:6379[1]> set k1 v1
OK
#删除数据库中的内容
127.0.0.1:6379[1]> flushdb
OK
#删除所有数据库中的内容
127.0.0.1:6379[1]> flushall
OK
#一次设置多个key value
127.0.0.1:6379[1]> mset username forest password 1qaz2wsx
OK
哈希存储和哈希算法
哈希存储-- 性能非常好的存储方案 --> set
obj --> 哈希函数 --> 哈希码(散列码) --> 对象在内存中存储的位置
文件 --> MD5 / SHA1 / SHA256 --> 哈希码
import hashlib
def cal_hash():
# md5 / sha1 / sha256
digester = hashlib.md5()
with open('requirements.txt','rb') as file_stream:
# 旧的做法
# data = file_stream.read(1024)
# while data:
# digester.update(data)
# data = file_stream.read(1024)
#使用迭代器,将文件改造为可迭代对象
file_iter = iter(lambda: file_stream.read(1024),b'')
for data in file_iter:
digester.update(data)
print(digester.hexdigest())
if __name__ == '__main__':
cal_hash()
#结果
ce443990290e094adeccfb4f21ee2d43
redis数据类型：hash + list +set + zset
hash表
#哈希表 hset key field value
[root@node1 ~]# redis-cli
#写入键值对
127.0.0.1:6379> hset stu1 id 1001
(integer) 1
#一次写入多个键值对
127.0.0.1:6379> hmset stu1 name yunqianqian gender female birth 1995-01-01 tel 13330116688
OK
#获取键值对
127.0.0.1:6379> hget stu1 id
"1001"
#一次获取所有键值对
127.0.0.1:6379> hvals stu1
1) "1001"
2) "yunqianqian"
3) "female"
4) "1995-01-01"
5) "13330116688"
127.0.0.1:6379> hgetall stu1
1) "id"
2) "1001"
3) "name"
4) "yunqianqian"
5) "gender"
6) "female"
7) "birth"
8) "1995-01-01"
9) "tel"
10) "13330116688"
#删除字段
127.0.0.1:6379> hdel stu1 tel
(integer) 1
#查看类型
127.0.0.1:6379> type stu1
hash
列表list
#列表
#从左往右放数据
127.0.0.1:6379> lpush numbers 10 20 30 40 50
(integer) 5
#展示数据
127.0.0.1:6379> lrange numbers 0 -1
1) "50"
2) "40"
3) "30"
4) "20"
5) "10"
#获取数据 lpop numbers [count]
127.0.0.1:6379> lpop numbers 3
1) "50"
2) "40"
3) "30"
#从右往左放数据
127.0.0.1:6379> rpush numbers 10 20 30 40 50
(integer) 7
127.0.0.1:6379> lrange numbers 0 -1
1) "20"
2) "10"
3) "10"
4) "20"
5) "30"
6) "40"
7) "50"
#每次只取一个元素，取完后最后一个报nil
127.0.0.1:6379> rpop numbers
"50"
127.0.0.1:6379> rpop numbers
"40"
127.0.0.1:6379> rpop numbers
"30"
127.0.0.1:6379> rpop numbers
"20"
127.0.0.1:6379> rpop numbers
"10"
127.0.0.1:6379> rpop numbers
"10"
127.0.0.1:6379> rpop numbers
"20"
127.0.0.1:6379> rpop numbers
(nil)
#取完数据后，类型即为none
127.0.0.1:6379> type numbers
none
127.0.0.1:6379> rpush numbers 10 20 30 40 50
(integer) 5
#重新存放之后，类型为list
127.0.0.1:6379> type numbers
list
集合set
#添加集合set
127.0.0.1:6379> sadd set 10 20 30 10 30 20 50 40 10 20
(integer) 5
#查看集合
127.0.0.1:6379> smembers set
1) "10"
2) "20"
3) "30"
4) "40"
5) "50"
#查看集合个数
127.0.0.1:6379> scard set
(integer) 5
#查看元素是否在集合中，在返回1，不在返回0
127.0.0.1:6379> sismember set 50
(integer) 1
127.0.0.1:6379> sismember set 80
(integer) 0
#添加新集合a b
127.0.0.1:6379> sadd a 1 2 3 4 5
(integer) 5
127.0.0.1:6379> sadd b 2 4 6 8 9
(integer) 5
#集合a b 求交集
127.0.0.1:6379> sinter a b
1) "2"
2) "4"
#集合a b 求并集
127.0.0.1:6379> sunion a b
1) "1"
2) "2"
3) "3"
4) "4"
5) "5"
6) "6"
7) "8"
8) "9"
#集合a b 求差集
127.0.0.1:6379> sdiff a b
1) "1"
2) "3"
3) "5"
#取集合元素
127.0.0.1:6379> spop a
"5"
127.0.0.1:6379> spop a 2
1) "3"
2) "4"
#查看剩余元素
127.0.0.1:6379> smembers a
1) "1"
2) "2"
#查看类型
127.0.0.1:6379> type a
set
有序集合 -- zset
#添加键值对
127.0.0.1:6379> zadd phb 100 chengzi 150 xiaoying 200 forest 380 orange
(integer) 4
#查看，默认升序排列
127.0.0.1:6379> zrange phb 0 -1
1) "chengzi"
2) "xiaoying"
3) "forest"
4) "orange"
#降序查看
127.0.0.1:6379> zrevrange phb 0 -1
1) "orange"
2) "forest"
3) "xiaoying"
4) "chengzi"
#给某个值刷票
127.0.0.1:6379> zincrby phb 1000 xiaoying
"1150"
127.0.0.1:6379> zrevrange phb 0 -1
1) "xiaoying"
2) "orange"
3) "forest"
4) "chengzi"
127.0.0.1:6379> zincrby phb 950 forest
"1150"
127.0.0.1:6379> zrevrange phb 0 -1
1) "xiaoying"
2) "forest"
3) "orange"
4) "chengzi"
127.0.0.1:6379>
redis地理位置距离计算
#添加地图坐标点，经度 纬度，
127.0.0.1:6379> geoadd map 104.0763 30.6234 libao 104.6072 30.6333 shumagc 104.7172 31.4594 mianyang
(integer) 3
#计算出来的是坐标点之间的直线距离，默认单位为米
127.0.0.1:6379> geodist map libao mianyang
"111249.2758"
127.0.0.1:6379> geodist map libao mianyang km
"111.2493"
#查看某坐标点50km 半径内的点
127.0.0.1:6379> georadius map 104.0 31.0 50 km
1) "libao"
127.0.0.1:6379> georadius map 104.0 31.0 50 km withdist
1) 1) "libao"
2) "42.5173"
127.0.0.1:6379> georadius map 104.0 31.0 100 km withdist
1) 1) "libao"
2) "42.5173"
2) 1) "shumagc"
2) "70.9060"
3) 1) "mianyang"
2) "85.2276"
127.0.0.1:6379> type map
zset
pycharm 连接redis
python 代码
import redis
def con_redis():
client = redis.Redis(host= '192.168.1.10',port= 6379, password='1qaz2wsx')
# client = redis.Redis(host= '192.168.1.10',port= 6379)
print(client)
client.set('username','hellokatty',ex=300)
print(client.ttl('username'))
print(client.get('username').decode())
client.set('nickname','forest')
print(client.get('nickname').decode())
client.set('Jerry',200)
client.incr('Jerry')
print(client.get('Jerry').decode())
client.incrby('Jerry',180)
print(client.get('Jerry').decode())
client.hset('student1','id',1001)
client.hset('student1','name','莫晓光')
print(client.hgetall('student1'))
print(client.hget('student1','name').decode())
client.rpush('list1',10,20,30,40,50)
print(client.lrange('list1',0,-1))
if __name__ == '__main__':
con_redis()
可能会出现报错 远程主机拒绝连接：
redis.exceptions.ConnectionError: Error 10061 connecting to 192.168.1.10:6379. No connection could be made because the target machine actively refused it.
解决办法：注释掉redis配置文件中的绑定本地主机 bind相关的都给注释掉，加上protected-mode no，关闭防火墙，然后重启redis
# Examples:
#
# bind 192.168.1.10 # listens on two specific IPv4 addresses
# bind 127.0.0.1 ::1 # listens on loopback IPv4 and IPv6
# bind * -::* # like the default, all available interfaces
#
# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
# internet, binding to all the interfaces is dangerous and will expose the
# instance to everybody on the internet. So by default we uncomment the
# following bind directive, that will force Redis to listen only on the
# IPv4 and IPv6 (if available) loopback interface addresses (this means Redis
# will only be able to accept client connections from the same host that it is
# running on).
#
# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
# JUST COMMENT OUT THE FOLLOWING LINE.
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# bind 127.0.0.1 -::1
# By default protected mode is enabled. You should disable it only if
# you are sure you want clients from other hosts to connect to Redis
# even if no authentication is configured, nor a specific set of interfaces
# are explicitly listed using the "bind" directive.
protected-mode no
#protected-mode yes
***************用努力照亮现实的梦！***********************
本文来自博客园，作者：逆流的鱼2016，转载请注明原文链接：https://www.cnblogs.com/orange2016/p/16797347.html
