Redis的String操作

set key value [ex 秒数] / [px 毫秒数]  [nx] /[xx]
如: set a 1 ex 10 , 10秒有效
Set a 1 px 9000  , 9秒有效
注: 如果ex,px同时写,以后面的有效期为准
如 set a 1 ex 100 px 9000, 实际有效期是9000毫秒
nx: 表示key不存在时,执行操作
xx: 表示key存在时,执行操作
127.0.0.1:6379> set site www.so.com
OK
127.0.0.1:6379> set site www.baidu.com nx
(nil)
127.0.0.1:6379> get site
"www.so.com"
127.0.0.1:6379> set site www.google.com xx
OK
127.0.0.1:6379> get site
"www.google.com"

mset  multi set , 一次性设置多个键值
例: mset key1 v1 key2 v2 ....
get key
作用:获取key的值
mget key1 key2 ..keyn
作用:获取多个key的值
127.0.0.1:6379> mset a aman b bold c controller
OK
127.0.0.1:6379> keys *
1) "a"
2) "c"
3) "b"
127.0.0.1:6379> get a
"aman"
127.0.0.1:6379> get b
"bold"
127.0.0.1:6379> get c
"controller"
127.0.0.1:6379> mget a b c
1) "aman"
2) "bold"
3) "controller"

setrange key offset value
作用:把字符串的offset偏移字节,改成value
127.0.0.1:6379> set word hello
OK
127.0.0.1:6379> get word
"hello"

0	1	2	3	4
h	e	l	l	o

127.0.0.1:6379> setrange word 2 ??
(integer) 5
127.0.0.1:6379> get word
"he??o"

注意: 如果偏移量>字符长度, 该字符自动补0x00

127.0.0.1:6379> set word hello
OK
127.0.0.1:6379> get word
"hello"
127.0.0.1:6379> setrange word 6 !
(integer) 7
127.0.0.1:6379> get word
"hello\x00!"

append key value
作用: 把value追加到key的原值上
127.0.0.1:6379> get word
"hello\x00!"
127.0.0.1:6379> append word @@
(integer) 9
127.0.0.1:6379> get word
"hello\x00!@@"

getrange key start stop
作用: 是获取字符串中 [start, stop]范围的值
注意: 对于字符串的下标,左数从0开始,右数从-1开始
127.0.0.1:6379> set area chinese
OK
127.0.0.1:6379> getrange area 1 4
"hine"

-7	-6	-5	-4	-3	-2	-1
w	o	r	k	i	n	g

127.0.0.1:6379> set status working
OK
127.0.0.1:6379> get status
"working"
127.0.0.1:6379> getrange status 0 -4
"work"

注意:

1: start>=length, 则返回空字符串

2: stop>=length,则截取至字符结尾

3: 如果start 所处位置在stop右边, 返回空字符串

getset key newvalue
作用: 获取并返回旧值,设置新值
127.0.0.1:6379> set status sleep
OK
127.0.0.1:6379> getset status wakeup
"sleep"
127.0.0.1:6379> get status
"wakeup"

incr key
作用: 指定的key的值加1,并返回加1后的值
注意:
1:不存在的key当成0,再incr操作
2: 范围为64有符号
decr key
作用: 指定的key的值减1,并返回减1后的值
incrby key number
decrby key number
127.0.0.1:6379> set age 29
OK
127.0.0.1:6379> incr age
(integer) 30
127.0.0.1:6379> decr age
(integer) 29
127.0.0.1:6379> incrby age 5
(integer) 34
127.0.0.1:6379> incrby age 5
(integer) 39
127.0.0.1:6379> decrby age 10
(integer) 29

setbit  key offset value
设置offset对应二进制位上的值
返回: 该位上的旧值可实现大小写转换

A	65	0	1	0	0	0	0	0	1
a	97	0	1	1	0	0	0	0	1

127.0.0.1:6379> set char A
OK
127.0.0.1:6379> get char
"A"
127.0.0.1:6379> setbit char 2 1
(integer) 0
127.0.0.1:6379> get char
"a"
127.0.0.1:6379> set char B
OK
127.0.0.1:6379> get char
"B"
127.0.0.1:6379> setbit char 2 1
(integer) 0
127.0.0.1:6379> get char
"b"