redis 基础数据类型Stirng（字符串）
常用命令
| 命令 |
说明 |
| set key value |
设置值 |
| get value |
获取值 |
| exists key |
判断1个key是否存在 |
| append key value |
追加字符串，key不存在时，即为set key |
| strlen key |
获取字符串的长度 |
| incr key |
自增1 |
| decr key |
自减1 |
| incrby key n |
自增n |
| decrby key n |
自减n |
| getrange key n1 n2 |
获取key对应字符串 [n1,n3] |
| getrange key 0 -1 |
获得key对应全部内容，相当于 get key |
| setrange key offset value |
将key对应字符串从 offset 开始的n(value长度)个字符替换为 value |
| setex key n value |
设置key值为value，n秒后过期 |
| setnx key value |
不存在时创建（存在时创建失败） |
| mset k1 v1 k2 v2 k3 v3 … |
同时设置多个值 |
| mget k1 k2 k3 … |
同时获取多个值 |
| msetnx k1 v1 k2 v2 … |
同时设置多个值（不存在，原子操作） |
| mset object:i:filed1:value1 … |
设置object对象，id为i，属性filed1对应值为value1 |
| mget object:i:filed1 onject:i:filed2 … |
获取id为 i 的object对象的属性filed1和filed2 |
| getset key value |
获取key原来的值，再设置新值 |
示例
[root@VM-0-10-centos ~]# redis-cli -p 6379
127.0.0.1:6379> set mykey hello
OK
127.0.0.1:6379> get mykey
"hello"
127.0.0.1:6379> exists key1
(integer) 0
127.0.0.1:6379> exists mykey
(integer) 1
127.0.0.1:6379> append mykey -world
(integer) 11
127.0.0.1:6379> get mykey
"hello-world"
127.0.0.1:6379> strlen mykey
(integer) 11
127.0.0.1:6379> set views 1
OK
127.0.0.1:6379> get views
"1"
127.0.0.1:6379> incr views
(integer) 2
127.0.0.1:6379> incr views
(integer) 3
127.0.0.1:6379> get views
"3"
127.0.0.1:6379> decr views
(integer) 2
127.0.0.1:6379> get views
"2"
127.0.0.1:6379> get views
"2"
127.0.0.1:6379> incrby views 10
(integer) 12
127.0.0.1:6379> get views
"12"
127.0.0.1:6379> decrby views 4
(integer) 8
127.0.0.1:6379> get views
"8"
127.0.0.1:6379> set mykey abcdefgh
OK
127.0.0.1:6379> get mykey
"abcdefgh"
127.0.0.1:6379> getrange mykey 0 3
"abcd"
127.0.0.1:6379> getrange mykey 0 -1
"abcdefgh"
127.0.0.1:6379> get mykey
"abcdefgh"
127.0.0.1:6379> setrange mykey 3 xxx
(integer) 8
127.0.0.1:6379> get mykey
"abcxxxgh"
127.0.0.1:6379> set mykey 10 hello
(error) ERR syntax error
127.0.0.1:6379> setex time 10 hello
OK
127.0.0.1:6379> ttl time
(integer) 6
127.0.0.1:6379> exists time
(integer) 0
127.0.0.1:6379> set mykey hello
OK
127.0.0.1:6379> get mykey
"hello"
127.0.0.1:6379> setnx mykey world
(integer) 0
127.0.0.1:6379> get mykey
"hello"
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 k3 v33 k4 v4
(integer) 0 ## 此处因为k3已经存在，所以会创建失败
127.0.0.1:6379> mget k1 k2 k3
1) "v1"
2) "v2"
3) "v3"
127.0.0.1:6379> mset user:1:name tony user:1:age 18
OK
127.0.0.1:6379> mget user:1:name user:1:age
1) "tony"
2) "18"
127.0.0.1:6379> set mykey hello
OK
127.0.0.1:6379> get mykey
"hello"
127.0.0.1:6379> getset mykey world
"hello"
127.0.0.1:6379> get mykey
"world"