Redis键值数据类型之字符串

Posted 2021-03-26 zoey686

字符串类型

 

1. 获得当前key="bar"对应value的类型

type bar

 

2. 字符串类型可以存储任何形式的字符串, 当存储的字符串是整数形式时, Redis提供了一个命令"incr", 让当前键值递增,并返回递增后的值

127.0.0.1:6379>  incr num
(integer) 1
127.0.0.1:6379>  incr num
(integer) 2
127.0.0.1:6379>  get num
"2"
127.0.0.1:6379>  type num
string

如果字符串不是整型数字,则会报错

127.0.0.1:6379> set str abcde
OK
127.0.0.1:6379> get str
"abcde"
127.0.0.1:6379> incr str
(error) ERR value is not an integer or out of range

 

3. 指定增加减少的整数

127.0.0.1:6379> set bar 0
OK
127.0.0.1:6379> incrby bar 1
(integer) 2
127.0.0.1:6379> incrby bar 3
(integer) 5
127.0.0.1:6379> get bar
"5"

减少
127.0.0.1:6379> decr bar
(integer) 4
127.0.0.1:6379> decrby 3
(error) ERR wrong number of arguments for ‘decrby‘ command
127.0.0.1:6379> decrby bar 3
(integer) 1

同时还有加上浮点数  incrbyfloat bar 1.1

 

4. 向尾部追加值, 获取字符串长度

127.0.0.1:6379> set key hello
OK
127.0.0.1:6379> append key " world!"
(integer) 12
127.0.0.1:6379> get key
"hello world!"
127.0.0.1:6379> strlen key
(integer) 12

 

5.同时获得/设置多个键值

127.0.0.1:6379> mset key1 v1 key2 v2 key3 v3
OK
127.0.0.1:6379> get key2
"v2"
127.0.0.1:6379> mget key2 key3
1) "v2"
2) "v3"

 

 总结:

 

 

总结图片来自: https://www.cnblogs.com/liqingwen/p/6919308.html

参考书籍《Redis入门指导》——李子骅 编著