一、有序集合使用场景

以某个条件为权重进行排序，比如按顶的次数排序。获得得分前100名用户，获取用户排名。比较适应做排行榜

二、有序集合主要命令

1、增

(1)zadd:将集合添加一个或多个成员、

用法：zadd key score member [score member]

如：在当前比较火的美女主播网站，某个礼物的排行榜，送出礼物为1001的用户排行榜

• 用户1001送出2个
• 1002送出20个
• 1010的用户送出1个

zadd gift:1001:ranking 2 user:1001 20 user:1002 1 user:1010

127.0.0.1:6379> zadd gift:1001:ranking 2 user:1002 20 user:1001 1 user:1010
(integer) 2
127.0.0.1:6379> zrange gift:1001:ranking 0 -1 withscores
1) "user:1010"
2) "1"
3) "user:1001"
4) "2"
5) "user:1002"
6) "20"

2、删

(1)zrem:删除集合中某个或某几个成员

用法：zrem key member [member]

如：发现排行榜中有些用户是刷礼物，则删除它，如删除排行榜用户为1002的成员

127.0.0.1:6379> zrem gift:1001:ranking user:1002
(integer) 1
127.0.0.1:6379> zrange gift:1001:ranking 0 -1 withscores
1) "user:1010"
2) "1"
3) "user:1001"
4) "20"

(2)zremrangebyscore：删除分数为指定范围的成员

用法：zremrangebyscore key min max

如：删除排行榜中数量为1至50的成员

127.0.0.1:6379> zrange gift:1001:ranking 0 -1 withscores
1) "user:1001"
2) "20"
3) "user:2321"
4) "22"
5) "user:2020"
6) "199"
7) "user:2567"
8) "2222"
127.0.0.1:6379> zremrangebyscore gift:1001:ranking 1 50
(integer) 2
127.0.0.1:6379> zrange gift:1001:ranking 0 -1 withscores
1) "user:2020"
2) "199"
3) "user:2567"
4) "2222"
```shell
###### (3)zremrangebyrank:删除某个指定范围的成员(成员按得分从小到大排)
用法：`zremrangebyrank key start stop`
如：
```shell
127.0.0.1:6379> zrange gift:1001:ranking 0 -1 withscores
 1) "user:1010"
 2) "3"
 3) "user:2452"
 4) "11"
 5) "user:1001"
 6) "20"
 7) "user:2321"
 8) "22"
 9) "user:2020"
10) "199"
11) "user:2567"
12) "2222"
127.0.0.1:6379> zremrangebyrank gift:1001:ranking 0 1
(integer) 2
127.0.0.1:6379> zrange gift:1001:ranking 0 -1 withscores
1) "user:1001"
2) "20"
3) "user:2321"
4) "22"
5) "user:2020"
6) "199"
7) "user:2567"
8) "2222"

3、改

(1)zincrby:增加某个成员的得分

用法：zincrby key increment member

如：增加用户1010的得分

127.0.0.1:6379> zrange gift:1001:ranking 0 -1 withscores
 1) "user:1010"
 2) "1"
 3) "user:2452"
 4) "11"
 5) "user:1001"
 6) "20"
 7) "user:2321"
 8) "22"
 9) "user:2020"
10) "199"
11) "user:2567"
12) "2222"
127.0.0.1:6379> zincrby gift:1001:ranking 2 user:1010
"3"
127.0.0.1:6379> zscore gift:1001:ranking user:1010
"3"

4、查

(1)zrange:根据索引查指定范围的成员(结果按得分从小到大排序)

用法：zrange key start end [withscores]

注：

• start或end如果是负数则从集合尾部开始读取
• 如果添加withscores这个参数会把成员的得分也返回

如：查询榜单所有成员

127.0.0.1:6379> zrange gift:1001:ranking 0 -1 withscores
 1) "user:1010"
 2) "1"
 3) "user:2452"
 4) "11"
 5) "user:1001"
 6) "20"
 7) "user:2321"
 8) "22"
 9) "user:2020"
10) "199"
11) "user:2567"
12) "2222"

查询得分最低的5个人

127.0.0.1:6379> zrange gift:1001:ranking 0 4 withscores
 1) "user:1010"
 2) "1"
 3) "user:2452"
 4) "11"
 5) "user:1001"
 6) "20"
 7) "user:2321"
 8) "22"
 9) "user:2020"
10) "199"

(2)zrevrange:根据索引查询指定范围的成员(结果按得分从大到小的排序，即倒序)

用法：zrevrange key start end [withscore]

如：获得排行榜的前3名

127.0.0.1:6379> zrevrange gift:1001:ranking 0 2 withscores
1) "user:2567"
2) "2222"
3) "user:2020"
4) "199"
5) "user:2321"
6) "22"

(3)zrevrangebyscore:查询得分在某个范围的成员(结果按分数从高往低排)

用法：zrevrangebyscore key max min [withscores] [limit offset count]

如：获得排行榜得分在200到1之间的用户

127.0.0.1:6379> zrevrangebyscore gift:1001:ranking 200 1 withscores
 1) "user:2020"
 2) "199"
 3) "user:2321"
 4) "22"
 5) "user:1001"
 6) "20"
 7) "user:2452"
 8) "11"
 9) "user:1010"
10) "1"

(4)zscore:获取某个成员的得分

用法:zscore key member

如：获取user:1001的分数

127.0.0.1:6379> zscore gift:1001:ranking user:1001 
"20"

(4)zrank:获取某个成员在集合中的索引值(可以理解为排名值，索引值是从0开始的，得分从低往高排)

用法：zrank key member

如：获取user:1001的索引值

127.0.0.1:6379> zrange gift:1001:ranking 0 -1
1) "user:1010"
2) "user:2452"
3) "user:1001"
4) "user:2321"
5) "user:2020"
6) "user:2567"
127.0.0.1:6379> zrank gift:1001:ranking user:1001
(integer) 2

(4)zrevrank:获取某个成员在集合中的排名(按得分从高到低)

用法：zrevrank key member

127.0.0.1:6379> zrevrange gift:1001:ranking 0 -1
1) "user:2567"
2) "user:2020"
3) "user:2321"
4) "user:1001"
5) "user:2452"
6) "user:1010"
127.0.0.1:6379> zrevrank gift:1001:ranking user:1001
(integer) 3

(5)zcard:获取集合的成员个数

用法：zcard key

如：获取排行榜中的人数

127.0.0.1:6379> zcard gift:1001:ranking
(integer) 6

(6)zcount:获取得分在指定范围内的成员的个数

用法：zcount key min max

如：获取得分在1到100之间的成员的个数

127.0.0.1:6379> zcount gift:1001:ranking 1 100
(integer) 4