【Redis 系列】redis 学习四，set 集合，hash 哈希，zset 有序集合初步认知 redis

set 集合
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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

【【Redis 系列】redis 学习四，set 集合，hash 哈希，zset 有序集合初步认知】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

【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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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

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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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