Redis的sorted_set的用法，看完这一篇就够了

最新推荐文章于 2024-05-04 09:38:05 发布

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最新推荐文章于 2024-05-04 09:38:05 发布

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分类专栏： Redis 文章标签： redis

本文链接：https://blog.csdn.net/H517604180/article/details/111601194

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各位小伙伴们，我们上次讲过Redis中Set的相关操作，以及适用的一些场景，例如抽奖等。今天要讲的sorted_set，其实也是set的一种，也具有set去重的特点。和set不同的是，sorted_set是有序的，从字面意思也可以看得出来。

那sorted_set是怎么排序的，根据什么规则排序呢？往下看。

我们先来看下sored_set提供了哪些命令。

127.0.0.1:6379> help @sorted_set
  BZPOPMAX key [key ...] timeout  summary: Remove and return the member with the highest score from one or more sorted sets, or block until one is available  since: 5.0.0
  BZPOPMIN key [key ...] timeout  summary: Remove and return the member with the lowest score from one or more sorted sets, or block until one is available  since: 5.0.0

  ZADD key [NX|XX] [CH] [INCR] score member [score member ...]  summary: Add one or more members to a sorted set, or update its score if it already exists  since: 1.2.0
  ZCARD key  summary: Get the number of members in a sorted set  since: 1.2.0
  ZCOUNT key min max  summary: Count the members in a sorted set with scores within the given values  since: 2.0.0
  ZINCRBY key increment member  summary: Increment the score of a member in a sorted set  since: 1.2.0
  ZINTERSTORE destination numkeys key [key ...] [WEIGHTS weight] [AGGREGATE SUM|MIN|MAX]  summary: Intersect multiple sorted sets and store the resulting sorted set in a new key  since: 2.0.0
  ZLEXCOUNT key min max  summary: Count the number of members in a sorted set between a given lexicographical range  since: 2.8.9
  ZPOPMAX key [count]  summary: Remove and return members with the highest scores in a sorted set  since: 5.0.0
  ZPOPMIN key [count]  summary: Remove and return members with the lowest scores in a sorted set  since: 5.0.0
  ZRANGE key start stop [WITHSCORES]  summary: Return a range of members in a sorted set, by index  since: 1.2.0
  ZRANGEBYLEX key min max [LIMIT offset count]  summary: Return a range of members in a sorted set, by lexicographical range  since: 2.8.9
  ZRANGEBYSCORE key min max [WITHSCORES] [LIMIT offset count]  summary: Return a range of members in a sorted set, by score  since: 1.0.5
  ZRANK key member  summary: Determine the index of a member in a sorted set  since: 2.0.0
  ZREM key member [member ...]  summary: Remove one or more members from a sorted set  since: 1.2.0
  ZREMRANGEBYLEX key min max  summary: Remove all members in a sorted set between the given lexicographical range  since: 2.8.9
  ZREMRANGEBYRANK key start stop  summary: Remove all members in a sorted set within the given indexes  since: 2.0.0
  ZREMRANGEBYSCORE key min max  summary: Remove all members in a sorted set within the given scores  since: 1.2.0
  ZREVRANGE key start stop [WITHSCORES]  summary: Return a range of members in a sorted set, by index, with scores ordered from high to low  since: 1.2.0
  ZREVRANGEBYLEX key max min [LIMIT offset count]  summary: Return a range of members in a sorted set, by lexicographical range, ordered from higher to lower strings.  since: 2.8.9
  ZREVRANGEBYSCORE key max min [WITHSCORES] [LIMIT offset count]  summary: Return a range of members in a sorted set, by score, with scores ordered from high to low  since: 2.2.0
  ZREVRANK key member  summary: Determine the index of a member in a sorted set, with scores ordered from high to low  since: 2.0.0
  ZSCAN key cursor [MATCH pattern] [COUNT count]  summary: Incrementally iterate sorted sets elements and associated scores  since: 2.8.0
  ZSCORE key member  summary: Get the score associated with the given member in a sorted set  since: 1.2.0
  ZUNIONSTORE destination numkeys key [key ...] [WEIGHTS weight] [AGGREGATE SUM|MIN|MAX]  summary: Add multiple sorted sets and store the resulting sorted set in a new key  since: 2.0.0

可以看到，sorted_set 中的命令大多以 Z 开头，因为set占用 S 了嘛。还有某些命令中有REV关键字，代表Reverse，反向的意思。

另外，还有两个命令以B开头，这里B代表Blocked，即阻塞的，上述帮助文档里也有说明（block until one is available）。

命令看起来挺多，我们大致做个分类。

sorted_set的基本用法

下面，我们来看下常用命令的具体用法。

一、基本操作

从ZADD命令可以看出，向key中添加元素时，有个参数score。没错，sorted_set 对每个元素都设定了分值，并在add时，根据这个分值进行升序排序。

  ZADD key [NX|XX] [CH] [INCR] score member [score member ...]  summary: Add one or more members to a sorted set, or update its score if it already exists  since: 1.2.0

/* 将笔试成绩（tom-100,jack-60,tony-80）放入名为 writtenTestScore 的有序集合里,返回元素个数3*/127.0.0.1:6379> zadd writtenTestScore 100 tom 60 jack 80 tony(integer) 3/面试成绩*/127.0.0.1:6379> zadd interviewScore 70 tom 80 jack 60 tony(integer) 3/*zrange列出所有元素*/127.0.0.1:6379> zrange writtenTestScore 0 -11) "jack"2) "tony"3) "tom"/*zrange列出所有元素（笔试成绩），带分值*/127.0.0.1:6379> zrange writtenTestScore 0 -1 withscores1) "jack"2) "60"3) "tony"4) "80"5) "tom"6) "100"/*列出面试成绩*/127.0.0.1:6379> zrange interviewScore 0 -1 withscores1) "tony"2) "60"3) "tom"4) "70"5) "jack"6) "80"下面是删除元素的一些操作，包括

ZPOPMAX/BZPOPMAX，ZPOPMIN/BZPOPMIN、ZREM等。

127.0.0.1:6379> ZADD testREM 1 a 2 b 3 c 4 d(integer) 4127.0.0.1:6379> zpopmax testREM 1) "d"2) "4"127.0.0.1:6379> zrem testREM a(integer) 1/*删除10个最大的元素并返回*/127.0.0.1:6379> zpopmax testREM 101) "c"2) "3"3) "b"4) "2"/*元素为空，阻塞1s后，返回空*/127.0.0.1:6379> BZPOPMAX testREM 1(nil)(1.01s/*取某个元素的分值*/127.0.0.1:6379> ZSCORE interviewScore tony"60"

二、统计类操作

统计类操作大致包括两类，一类是取元素的个数或排名，一类是取元素的列表。

/*列出80-100分数段的元素个数*/127.0.0.1:6379> zcount writtenTestScore 80 100(integer) 2/*返回集合中元素个数*/127.0.0.1:6379> zcard writtenTestScore (integer) 3/*取jack的排名*/127.0.0.1:6379> ZRANK writtenTestScore jack(integer) 0

/*取出80-100分数段的元素*/127.0.0.1:6379> ZRANGEBYSCORE writtenTestScore 80 100 withscores1) "tony"2) "80"3) "tom"4) "100"/*取笔试分数最高的前两名*/127.0.0.1:6379> ZREVRANGE writtenTestScore 0 1 withscores1) "tom"2) "100"3) "tony"4) "80"

三、运算类操作

127.0.0.1:6379> ZRANGE writtenTestScore 0 -1 withscores1) "jack"2) "60"3) "tony"4) "80"5) "tom"6) "100"
对jack的分值进行加法运算后，jack排到了第二个位置。

127.0.0.1:6379> ZINCRBY writtenTestScore 30 jack"90"127.0.0.1:6379> ZRANGE writtenTestScore 0 -1 withscores1) "tony"2) "80"3) "jack"4) "90"5) "tom"6) "100"

也就是说，sorted_set 对集合的每一次变更，都随时维护着一个按分值排序的顺序。

下面来看并集与交集的操作。

为了方便理解交集和并集，我们分别对writtenTestScore和

interview_Score进行增加元素的操作。即polly只参加了笔试，lucy只参加了面试。

127.0.0.1:6379> zadd writtenTestScore 50 polly (integer) 1127.0.0.1:6379> ZRANGE writtenTestScore 0 -1 withscores1) "polly"2) "50"3) "tony"4) "80"5) "jack"6) "90"7) "tom"8) "100"127.0.0.1:6379> zadd interviewScore 50 lucy(integer) 1127.0.0.1:6379> ZRANGE interviewScore 0 -1 withscores1) "lucy"2) "50"3) "tony"4) "60"5) "tom"6) "70"7) "jack"8) "80"
假设现在要根据笔试（权重0.6）和面试（权重0.4）的总分数进行排序，可以用 ZUNIONSTORE 来实现。

127.0.0.1:6379> ZUNIONSTORE result 2 writtenTestScore interviewScore weights 0.6 0.4 aggregate sum(integer) 5/*lucy只参加了面试，50*0.4=20; tony笔试80*0.6+面试60*0.4=72*/127.0.0.1:6379> ZRANGE result 0 -1 withscores 1) "lucy" 2) "20" 3) "polly" 4) "30" 5) "tony" 6) "72" 7) "jack" 8) "86" 9) "tom"10) "88"

假设需求有变化，增加条件限制：面试和笔试都参加的。此时，可以使用集合交集运算 ZINTERSTORE。

127.0.0.1:6379> ZINTERSTORE result 2  writtenTestScore interviewScore weights 0.6 0.4 aggregate sum(integer) 3127.0.0.1:6379> ZRANGE result 0 -1 withscores1) "tony"2) "72"3) "jack"4) "86"5) "tom"6) "88"

关于sorted_set的排序算法

sorted_set对于集合变更的操作，例如zadd，zrem，zpop，zincrby等，都随时维护着一个排序。

简单理解，这里的排序算法是用skipList（跳表）实现的。举个例子，跳表的算法类似于，我们找书上的某一页，会先找到目录一样。当然，跳表的“目录”可能不止一层。

总结

稍微总结一下，本次分享了sorted_set的三种类型的操作，分别是基本操作（包括添加、删除）、统计类（集合中符合某些条件的元素个数、排名、元素列表）操作以及运算类（交集、并集、加法）操作。

sorted_set一般适用于排行榜，例如按照动态的点赞数（作为set中key的分值）、帖子的点击率排名等场景。

简单理解，sorted_set使用跳表实现的。

好了，本次分享就是这样，我们下次见。

关注我，持续输出技术干货。

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Redis的sorted_set的用法，看完这一篇就够了

各位小伙伴们，我们上次讲过Redis中Set的相关操作，以及适用的一些场景，例如抽奖等。今天要讲的sorted_set，其实也是set的一种，也具有set去重的特点。和set不同的是，sorted_set是有序的，从字面意思也可以看得出来。那sorted_set是怎么排序的，根据什么规则排序呢？往下看。我们先来看下sored_set提供了哪些命令。127.0.0.1:6379> help @sorted_set BZPOPMAXkey[key...]timeout summ...
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