（免费领取红包封面）【Redis 系列】redis 学习四，set 集合，hash 哈希，zset 有序集合初步认知

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set 集合

set 集合里面的数据是不能重读的

• SADD key member [member ...]

向 set 集合中添加元素

• SMEMBERS key

查看集合中的所有元素

• SISMEMBER key member

查看某一个数据是否在集合中

• SCARD key

查看集合数据的个数，也就是集合的长度

• SREM key member [member ...]

移除集合中指定的元素

127.0.0.1:6379> sadd myset "hello"
(integer) 1
127.0.0.1:6379> sadd myset "wolrd" "xiaomotong"
(integer) 2
127.0.0.1:6379> SMEMBERS myset
1) "wolrd"
2) "xiaomotong"
3) "hello"
127.0.0.1:6379> SISMEMBER myset hello
(integer) 1
127.0.0.1:6379> SCARD myset
(integer) 3
127.0.0.1:6379> SREM myset wolrd
(integer) 1
127.0.0.1:6379> SMEMBERS myset
1) "xiaomotong"
2) "hello"

• SRANDMEMBER key [count]

随机获取集合里面的数据，可以指定个数

127.0.0.1:6379> sadd myset "v1" "v2" "v3" "v4"
(integer) 4
127.0.0.1:6379> SMEMBERS myset
1) "v4"
2) "xiaomotong"
3) "v1"
4) "v2"
5) "hello"
6) "v3"
127.0.0.1:6379> SRANDMEMBER myset
"v2"
127.0.0.1:6379> SRANDMEMBER myset
"xiaomotong"
127.0.0.1:6379> SRANDMEMBER myset 2
1) "v4"
2) "v1"
127.0.0.1:6379>
127.0.0.1:6379> SRANDMEMBER myset 2
1) "xiaomotong"
2) "v1"

• SPOP key [count]

随机删除集合中的任意元素

127.0.0.1:6379> SMEMBERS myset
1) "v4"
2) "xiaomotong"
3) "v1"
4) "v2"
5) "hello"
6) "v3"
127.0.0.1:6379> SPOP myset
"v2"
127.0.0.1:6379> SMEMBERS myset
1) "v4"
2) "xiaomotong"
3) "v1"
4) "hello"
5) "v3"
127.0.0.1:6379> SPOP myset
"v4"
127.0.0.1:6379> SMEMBERS myset
1) "xiaomotong"
2) "v1"
3) "hello"
4) "v3"

• SMOVE source destination member

从指定的集合中取出一个元素，放到另外一个集合中

127.0.0.1:6379> SMEMBERS myset
1) "xiaomotong"
2) "v1"
3) "hello"
4) "v3"
127.0.0.1:6379> SMEMBERS myset
1) "xiaomotong"
2) "v1"
3) "hello"
4) "v3"
127.0.0.1:6379> SMOVE myset newset v1
(integer) 1
127.0.0.1:6379> SMEMBERS newset
1) "v1"
127.0.0.1:6379> SMEMBERS myset
1) "xiaomotong"
2) "hello"
3) "v3"

• SUNION key [key ...]

取并集，对两个集合取并集

• SINTER key [key ...]

取交集，对两个集合取交集

127.0.0.1:6379> SMEMBERS myset
1) "xiaomotong"
2) "hello"
3) "v3"
127.0.0.1:6379> sadd newset v3
(integer) 1
127.0.0.1:6379> sadd newset v6 v9
(integer) 2
127.0.0.1:6379> SUNION myset newset
1) "v3"
2) "hello"
3) "xiaomotong"
4) "v1"
5) "v6"
6) "v9"
127.0.0.1:6379> SINTER myset newset
1) "v3"
127.0.0.1:6379>

set 应用场景可以有，多个用户的共同关注，好友推荐，共同的粉丝，功能的爱好等等

hash 哈希

Map 集合，key-map，此时 key-value 是一个集合，本质上和 string 类型没有啥区别，还是一个简单的 key-value 形式

• HSET key field value [field value ...] / HMSET key field value [field value ...]

在 hash key 中添加 1 个或者多个 key-value

• HGET key field

获取 hash 里面的一个 key 对应的 value

• HMGET key field [field ...]

获取 hash 里面的多个 key 对应的 value

• HGETALL key

获取 hash 里面所有的 键值对

127.0.0.1:6379> hset myhash name xiaomotong age 12 hobby play
(integer) 3
127.0.0.1:6379> hget myhash name
"xiaomotong"
127.0.0.1:6379> hmget myhash name age
1) "xiaomotong"
2) "12"
127.0.0.1:6379> hgetall myhash
1) "name"
2) "xiaomotong"
3) "age"
4) "12"
5) "hobby"
6) "play"

• HDEL key field [field ...]

删除 hash 里面的 key，一个或者多个

127.0.0.1:6379> HSET myhash k1 v1 k2 v2 k3 v3
(integer) 3
127.0.0.1:6379> hgetall
(error) ERR wrong number of arguments for 'hgetall' command
127.0.0.1:6379> hgetall myhash
 1) "age"
 2) "12"
 3) "hobby"
 4) "play"
 5) "k1"
 6) "v1"
 7) "k2"
 8) "v2"
 9) "k3"
10) "v3"
127.0.0.1:6379> HDEL myhash k1 k2
(integer) 2
127.0.0.1:6379> HDEL myhash name
(integer) 1
127.0.0.1:6379> hgetall myhash
1) "age"
2) "12"
3) "hobby"
4) "play"
5) "k3"
6) "v3"

• HLEN key

获取 hash 的长度，也就是 key-value 的对数

127.0.0.1:6379> HLEN myhash
(integer) 3

• HINCRBY key field increment

在集合中的某个 key 上增加值，若值是正数，则是加，若值是负数则是减

• HSETNX key field value

向 hash 中加入键值对，若不存在则添加，存在则添加失败

127.0.0.1:6379> hset myhash age 12
(integer) 1
127.0.0.1:6379> HINCRBY myhash age 2
(integer) 14
127.0.0.1:6379> HINCRBY myhash age -1
(integer) 13
127.0.0.1:6379> HSETNX myhash name xiaozhu
(integer) 1
127.0.0.1:6379> HSETNX myhash name xiaopangzi
(integer) 0
127.0.0.1:6379> hgetall myhash
1) "age"
2) "13"
3) "name"
4) "xiaopangzi"

hash 的应用场景有，经常变更数据的地方，尤其是一些用户的信息，经常变动的信息

hash 更适合对象的存储，string 更加适合字符串的存储

zset 有序集合

zset 也是集合，只是在 set 的基础上加上了一个值

• ZADD key [NX|XX] [GT|LT] [CH] [INCR] score member [score member ...]

向有序集合中添加 分数 和 值，可以添加多个

• ZRANGEBYSCORE key min max [WITHSCORES] [LIMIT offset count]

按照分数的顺序排序，-inf 为负无穷，+inf 为正无穷

• ZRANGE key min max [BYSCORE|BYLEX] [REV] [LIMIT offset count] [WITHSCORES]

查看有序集合里面的所有的值

127.0.0.1:6379> ZADD myage 10 xiaoming 8 xiaohong 19 xiaozhu
(integer) 3
127.0.0.1:6379> ZRANGEBYSCORE myage 0 -1
(empty array)
127.0.0.1:6379> ZRANGEBYSCORE myage -inf +inf
1) "xiaohong"
2) "xiaoming"
3) "xiaozhu"
127.0.0.1:6379> ZRANGEBYSCORE myage -inf +inf withscores
1) "xiaohong"
2) "8"
3) "xiaoming"
4) "10"
5) "xiaozhu"
6) "19"
127.0.0.1:6379> ZRANGEBYSCORE myage -inf 10
1) "xiaohong"
2) "xiaoming"
127.0.0.1:6379> ZRANGE myage 0 -1
1) "xiaohong"
2) "xiaoming"
3) "xiaozhu"

• ZREM key member [member ...]

删除有序集合里面的数据

127.0.0.1:6379> ZREM myage xiaoming
(integer) 1
127.0.0.1:6379> ZRANGEBYSCORE myage -inf +inf withscores
1) "xiaohong"
2) "8"
3) "xiaozhu"
4) "19"

• ZREVRANGE key start stop [WITHSCORES]

对有序集合从大到小排序

127.0.0.1:6379> ZADD myage 7 xiaohe 17 xiaoliu 14 huhu
(integer) 3
127.0.0.1:6379> ZRANGE myage 0 -1
1) "xiaohe"
2) "xiaohong"
3) "huhu"
4) "xiaoliu"
5) "xiaozhu"
127.0.0.1:6379> ZRANGEBYSCORE myage -1 20
1) "xiaohe"
2) "xiaohong"
3) "huhu"
4) "xiaoliu"
5) "xiaozhu"
127.0.0.1:6379> ZRANGEBYSCORE myage -1 20 withscores
 1) "xiaohe"
 2) "7"
 3) "xiaohong"
 4) "8"
 5) "huhu"
 6) "14"
 7) "xiaoliu"
 8) "17"
 9) "xiaozhu"
10) "19"
127.0.0.1:6379> ZREVRANGE myage 0 -1
1) "xiaozhu"
2) "xiaoliu"
3) "huhu"
4) "xiaohong"
5) "xiaohe"

其余的 api 我们可以到 redis 官网上去进行学习和实践，可以查看 redis 官方的中文文档，http://www.redis.cn/

zset 的应用场景有：

set 排序，存储班级成绩信息，工资信息等等，用于排序和筛选的

带有权重的数据或者消息，排行榜的实现等等

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