Redis 学习笔记String操作

Posted 2021-05-29 Adorable_Rocy

1.基本set&get设置和获取值

127.0.0.1:6379> set k1 v1
OK
127.0.0.1:6379> get k1
"v1"
127.0.0.1:6379> 

2.expire key second

127.0.0.1:6379> expire k1 30 # 设置30秒后失效
(integer) 1
127.0.0.1:6379> ttl k1 # 查看失效时间
(integer) 26
127.0.0.1:6379> ttl k1 
(integer) 23
127.0.0.1:6379> ttl k1
(integer) 20
127.0.0.1:6379> get k1  # 过了30s再去获取值已经失效
(nil)
127.0.0.1:6379> ttl k1
(integer) -2   # 失效后的值为-2

3.append key val

127.0.0.1:6379> append k1 "hello" # 追加字符串，如果键不存在，相当于set k v
(integer) 5
127.0.0.1:6379> get k1
"hello

4.strlen key

127.0.0.1:6379> STRLEN k1 # 获取键的长度
(integer) 5

5.incr key

127.0.0.1:6379> set views 0 # 设置初始化的值
OK
127.0.0.1:6379> INCR views # 自增1
(integer) 1
127.0.0.1:6379> INCR views
(integer) 2
127.0.0.1:6379> get views
"2"
127.0.0.1:6379> 

6.decr key

127.0.0.1:6379> DECR views # 完成自减
(integer) 1
127.0.0.1:6379> DECR view # 如果不存在键 自减并且创建键
(integer) -1 
127.0.0.1:6379> DECR views
(integer) 0
127.0.0.1:6379> DECR view
(integer) -2
127.0.0.1:6379> keys *
1) "views"
2) "k1"
3) "view"

7.incrby key

127.0.0.1:6379> INCRBY views 10 # 连增
(integer) 10
127.0.0.1:6379> INCRBY views 11
(integer) 21
127.0.0.1:6379> 

8.decrby key

127.0.0.1:6379> DECRBY views 15 # 连减
(integer) 6
127.0.0.1:6379> DECRBY views 10
(integer) -4
127.0.0.1:6379> 

9.getrange key [ index lastindex ]

127.0.0.1:6379> set name "fat" 
OK
127.0.0.1:6379> APPEND name "cat,welcome"
(integer) 14
127.0.0.1:6379> GETRANGE name 0 -1 # 获取所有内容
"fatcat,welcome"
127.0.0.1:6379> GETRANGE name 0 3 # 获取指定索引 （闭区间）
"fatc"
127.0.0.1:6379> 

10.setrange key index val

127.0.0.1:6379> GETRANGE name 0 -1
"fatcat,welcome"
127.0.0.1:6379> SETRANGE name 0 abc # 替换开始索引后的数据
(integer) 14
127.0.0.1:6379> GETRANGE name 0 -1
"abccat,welcome"

11.setex key sencond val

# setex (set with expire) 设置过期时间
127.0.0.1:6379> setex mcode 10 "msgcode" # 设置10秒失效
OK
127.0.0.1:6379> ttl mcode
(integer) 4
127.0.0.1:6379> ttl mcode
(integer) -2
127.0.0.1:6379> get mcode 
(nil) 
127.0.0.1:6379> 

12.setnx key val

# setnx (set if not exists)
127.0.0.1:6379> SETNX mymsg "notexists" # 如果不存在才会被创建
(integer) 1
127.0.0.1:6379> GETRANGE mymsg 0 -1
"notexists"
127.0.0.1:6379> SETNX mymsg "fixmymsg" # 修改内容
(integer) 0  # 这里是没有被修改的，因为无法修改
127.0.0.1:6379> GETRANGE mymsg 0 -1
"notexists"
127.0.0.1:6379> 

13.mset k1 v1 k2 v2 …

# mset 批量设置
# mget 批量获取
127.0.0.1:6379> FLUSHdb # 清空当前库缓存 FLUSHALL # 清空全部库缓存
OK
127.0.0.1:6379> mset k1 v1 k2 v2 k3 v3
OK
127.0.0.1:6379> mget k1 k2 k3
1) "v1"
2) "v2"
3) "v3" 
127.0.0.1:6379> msetnx k1 v1 k4 v4 # msetnx 原子性操作
(integer) 0 
127.0.0.1:6379> get k4
(nil)
127.0.0.1:6379> 

14.对象

# 使用json串的形式储存对象
127.0.0.1:6379> set user:1 {name:zhangsan,age:18}
OK
127.0.0.1:6379> get user:1
"{name:zhangsan,age:18}"
127.0.0.1:6379> 
# 使用模板 user:{id}:{filed}
127.0.0.1:6379> mset user:1:name zhangsan user:1:age 20
OK
127.0.0.1:6379> mget user:1:name user:1:age
1) "zhangsan"
2) "20"
127.0.0.1:6379> 

15.getset key val

127.0.0.1:6379> FLUSHdb 
OK
127.0.0.1:6379> getset k1 v1 # 先获取原来的值 再进行设置值
(nil)
127.0.0.1:6379> get k1 # 获取新值
"v1"
127.0.0.1:6379> getset k1 newv1 # 设置新值
"v1"
127.0.0.1:6379> get k1
"newv1" # 获取新值
127.0.0.1:6379>