redis常用五种数据类型----String类型的基本操作

左手的ㄟ右手 2023-02-24 08:57 11阅读 0赞

# 基本命令的使用参考:   [http://redisdoc.com/][http_redisdoc.com] #

*  ## String的存储类型 ##

1.  INT  整型
2.  Float  浮点型
3.  String  字符串

127.0.0.1:6379> select 1
    OK
    127.0.0.1:6379[1]> set name hz
    OK
    127.0.0.1:6379[1]> get name
    "hz"
    127.0.0.1:6379[1]> flushdb
    OK
    127.0.0.1:6379[1]> keys *
    (empty list or set)
    127.0.0.1:6379[1]> flushall
    OK
    127.0.0.1:6379[1]> set name
    (error) ERR wrong number of arguments for 'set' command
    127.0.0.1:6379[1]> dbsize
    (integer) 0
    127.0.0.1:6379[1]> exists hz
    (integer) 0
    127.0.0.1:6379[1]> set hz 111
    OK
    127.0.0.1:6379[1]> exists hz
    (integer) 1
    127.0.0.1:6379[1]> dbsize
    (integer) 1
    127.0.0.1:6379[1]> type hz
    string
    127.0.0.1:6379[1]> del hz
    (integer) 1
    127.0.0.1:6379[1]> keys *
    (empty list or set)
    127.0.0.1:6379[1]> mset hh 111 jj 222
    OK
    127.0.0.1:6379[1]> mget hh jj
    1) "111"
    2) "222"
    127.0.0.1:6379[1]> setnx hh 111
    (integer) 0
    127.0.0.1:6379[1]> setnx hhh 111
    (integer) 1
    127.0.0.1:6379[1]> EXPIRE lock 10
    (integer) 0
    127.0.0.1:6379[1]> set lock 111
    OK
    127.0.0.1:6379[1]> EXPIRE lock 10
    (integer) 1
    127.0.0.1:6379[1]> get lock
    "111"
    127.0.0.1:6379[1]> get lock
    (nil)
    127.0.0.1:6379[1]> get lock
    (nil)
    127.0.0.1:6379[1]> clear
    127.0.0.1:6379[1]> set lock 111 EX 10 NX    //可以实现分布式锁   EX 10  标识10秒过期   NX不存在的时候才能设置
    OK
    127.0.0.1:6379[1]> get lock
    "111"
    127.0.0.1:6379[1]> get lock
    (nil)
    127.0.0.1:6379[1]>  clear
    127.0.0.1:6379[1]> set huangzhen 111
    OK
    127.0.0.1:6379[1]> incr huangzhen
    (integer) 112
    127.0.0.1:6379[1]> decr huangzhn
    (integer) -1
    127.0.0.1:6379[1]> decr huangzhen
    (integer) 111
    127.0.0.1:6379[1]> decr huangzhen
    (integer) 110
    127.0.0.1:6379[1]> set f 2.2
    OK
    127.0.0.1:6379[1]> incrbyfloat f 7.7
    "9.9"
    127.0.0.1:6379[1]> append huangzhen goodman
    (integer) 10
    127.0.0.1:6379[1]> get huangzhne
    (nil)
    127.0.0.1:6379[1]> get huangzhen
    "110goodman"
    127.0.0.1:6379[1]> strlen huangzhen
    (integer) 10
    127.0.0.1:6379> getrange huangzhen 0 -1
    "111goodman"
    127.0.0.1:6379> getrange huangzhen 0 4
    "111go"

*  ### String 应用场景 ###

1.  缓存
2.  分布式Session
3.  set EX NX 实现分布式锁
4.  incr   分库分表全局id的实现
5.  incr   计数器（文章阅读量，微博点赞数,不需要实时同步到数据库）
6.  incy  限流
7.  位操作

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