Redis之zset类型

1. 添加元素/获取集合中元素的数量

添加元素：ZADD key score member [score member …]
获取集合中元素的数量：ZCARD key

127.0.0.1:6379> zadd z1 100 apple 200 banana
(integer) 2
127.0.0.1:6379> zcard z1
(integer) 2

2. 按照元素分数从小到大的顺序返回索引从start到stop之间的所有元素

ZRANGE key start stop [WITHSCORES]

127.0.0.1:6379> zrange z1 0 -1
1) "apple"
2) "banana"

3. 获取元素的分数

ZSCORE key member

127.0.0.1:6379> zscore z1 apple
"100"
127.0.0.1:6379> zscore z1 banana
"200"

4. 删除元素

ZREM key member [member …]

127.0.0.1:6379> zrem z1 banana
(integer) 1
127.0.0.1:6379> zcard z1
(integer) 1
127.0.0.1:6379> zrange z1 0 -1
1) "apple"

5. 获取指定分数范围的元素

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

127.0.0.1:6379> zadd z1 200 banana 300 pear 400 peach
(integer) 3
127.0.0.1:6379> zcard z1
(integer) 4
127.0.0.1:6379> zrangebyscore z1 200 400
1) "banana"
2) "pear"
3) "peach"
127.0.0.1:6379> zrangebyscore z1 100 300
1) "apple"
2) "banana"
3) "pear"

6. 增加某个元素的分数

ZINCRBY key increment member

127.0.0.1:6379> zincrby z1 50 apple
"150"
127.0.0.1:6379> zscore z1 apple
"150"

7. 获得指定分数范围内的元素个数

ZCOUNT key min max

127.0.0.1:6379> zcount z1 200 400
(integer) 3
127.0.0.1:6379> zcount z1 100 400
(integer) 4

8. 获取元素的排名

从小到大：ZRANK key member
从大到小：ZREVRANK key member

127.0.0.1:6379> zrank z1 apple
(integer) 0
127.0.0.1:6379> zrank z1 peach
(integer) 3
127.0.0.1:6379> zrevrank z1 peach
(integer) 0
127.0.0.1:6379> zrevrank z1 apple
(integer) 3

9. 按照排名范围内删除元素

ZREMRANGEBYRANK key start stop

127.0.0.1:6379> zremrangebyrank z1 0 -1
(integer) 4
127.0.0.1:6379> zcard z1
(integer) 0
127.0.0.1:6379> zrange z1 0 -1
(empty list or set)

10. 应用场景

10.1 商品销量排名

定义商品销量排行榜(sorted set集合)，key为goods:sellsort，分数为商品销售数量。
商品编号1001销量9，1002销量12，1003销量15…
zadd goods:sellsort 9 1001 12 1002 15 1003 18 1004 21 1005 16 1006
有一个客户又买了5件商品1001：zincrby goods:sellsort 5 1001
商品销量由低到高销量前10名：zrange goods:sellsort 0 10 withscores
商品销量由高到低销量前10名：zrevrange goods:sellsort 0 10 withscores

127.0.0.1:6379> zadd goods:sellsort 9 1001 12 1002 15 1003 18 1004 21 1005 16 1006
(integer) 6
127.0.0.1:6379> zincrby goods:sellsort 5 1001
"14"
127.0.0.1:6379> zrange goods:sellsort 0 10 withscores1) "1002"2) "12"3) "1001"4) "14"5) "1003"6) "15"7) "1006"8) "16"9) "1004"
10) "18"
11) "1005"
12) "21"
127.0.0.1:6379> zrevrange goods:sellsort 0 10 withscores1) "1005"2) "21"3) "1004"4) "18"5) "1006"6) "16"7) "1003"8) "15"9) "1001"
10) "14"
11) "1002"
12) "12"
127.0.0.1:6379> zrevrange goods:sellsort 0 3 withscores
1) "1005"
2) "21"
3) "1004"
4) "18"
5) "1006"
6) "16"
7) "1003"
8) "15"

10.2 抖音热搜

点击视频一次访问次数加1：zincrby hotsearch:20230927 1 movie1
造数据movie1 11次，movie2 10次，movie3 18次
对访问次数又高到底显示前10名：zrevrange hotsearch:20230927 0 9 withscores

127.0.0.1:6379> zincrby hotsearch:20230927 1 movie1
"1"
127.0.0.1:6379> zincrby hotsearch:20230927 10 movie1
"11"
127.0.0.1:6379> zincrby hotsearch:20230927 10 movie2
"10"
127.0.0.1:6379> zincrby hotsearch:20230927 18 movie3
"18"
127.0.0.1:6379> zrevrange hotsearch:20230927 0 9 withscores
1) "movie3"
2) "18"
3) "movie1"
4) "11"
5) "movie2"
6) "10"