Redis Sorted Sets (sorted set)

Redis有序集合和集合一样也是string类型元素的集合，且不允许重复的成员。

The difference is that each element is associated with a double type of score. Redis sorts the members in the set from small to large through scores.

The members of the ordered set are unique, but the score (score) can be repeated.

The collection is implemented by hash table, so the complexity of adding, deleting, and searching is O(1) 2³² - 1 (4294967295, each collection can store40 to 1 billion members).

Online examples

redis　127.0.0.1:6379>  ZADD w3codeboxkey　1　redis
(integer)　1
redis　127.0.0.1:6379>  ZADD w3codeboxkey　2　mongodb
(integer)　1
redis　127.0.0.1:6379>  ZADD w3codeboxkey　3　mysql
(integer)　1
redis　127.0.0.1:6379>  ZADD w3codeboxkey　3　mysql
(integer) 0
redis　127.0.0.1:6379>  ZADD w3codeboxkey　4　mysql
(integer) 0
redis　127.0.0.1:6379>  ZRANGE w3codeboxkey 0　10　WITHSCORES
1)  "redis"
2) "1"
3)  "mongodb"
4) "2"
5)  "mysql"
6) "4"

In the above example, we use the command ZADD Three values were added to the redis ordered set and associated with scores.

Redis ordered set commands

The following table lists the basic commands of redis ordered set: