Redis ordered set (sorted set)

Redis ordered set (sorted set)

A Redis ordered collection is a collection of elements of type string, as well as a collection, and does not allow duplicate members.

The difference is that each element is associated with a double-type fraction. Redis is a small-to-large ordering of the members in a collection by fractions.

The members of an ordered collection are unique, but fractions (score) can be duplicated.

The collection is implemented by a hash table, so the complexity of adding, deleting, and finding is O (1). The maximum number of members in the collection is 232-1 (4294967295, each of which can store 40多亿个 members).

Instance

Redis127.0.0.1:6379>Zadd Runoobkey1Redis(Integer) 1Redis127.0.0.1:6379>Zadd Runoobkey2Mongodb(Integer) 1Redis127.0.0.1:6379>Zadd Runoobkey3Mysql(Integer) 1Redis127.0.0.1:6379>Zadd Runoobkey3Mysql(Integer) 0Redis127.0.0.1:6379>Zadd Runoobkey4Mysql(Integer) 0Redis127.0.0.1:6379> Zrange runoobkey 0  10 Withscores1)   "Redis" 2  "1" 3)   "MongoDB" 4)   "2" 5)   "MySQL" 6)   "4"             

In the above example we add three values to the ordered set of Redis and associate the scores with the command Zadd .

Redis ordered Collection command

The following table lists the basic commands for the Redis ordered collection:

Serial Number	Command and Description
1	Zadd key Score1 member1 [Score2 member2] Add one or more members to an ordered collection, or update a fraction of an existing member
2	Zcard Key Gets the number of members of an ordered collection
3	Zcount Key min Max Calculates the number of members that specify interval fractions in an ordered set
4	Zincrby Key Increment member The fractional plus increment of the specified member in an ordered collection increment
5	Zinterstore destination Numkeys key [key ...] Computes the intersection of the given one or more ordered sets and stores the result set in the new ordered collection key
6	Zlexcount Key min Max Calculates the number of members within a specified dictionary interval in an ordered collection
7	Zrange key start stop [Withscores] Returns an ordered set of members within a specified range by an index interval
8	Zrangebylex key min Max [LIMIT offset Count] Returning members of an ordered collection through a dictionary interval
9	Zrangebyscore key min Max [withscores] [LIMIT] Returns the members of an ordered set within a specified interval by a fraction
10	Zrank Key Member Returns the index of the specified member in an ordered collection
11	Zrem key member [member ...] To remove one or more members from an ordered collection
12	Zremrangebylex Key min Max Removes all members of a given dictionary interval in an ordered collection
13	Zremrangebyrank Key Start stop Removes all members of a given rank range in an ordered collection
14	Zremrangebyscore Key min Max Removes all members of a given fractional interval in an ordered collection
15	Zrevrange key start stop [Withscores] Returns the members of the specified interval in an ordered set, through the index, the score from the high end
16	Zrevrangebyscore key Max min [Withscores] Returns the members in the specified fractional interval in an ordered set, sorted from highest to lowest
17	Zrevrank Key Member Returns the rank of the specified member in an ordered collection, sorted by the descending (large to small) fractional value of the ordered set member
18	Zscore Key Member Returns the fractional value of a member in an ordered set
19	Zunionstore destination Numkeys key [key ...] Calculates the set of a given one or more ordered sets and stores it in a new key
20	Zscan key cursor [MATCH pattern] [count Count] Iterate elements in an ordered collection (including element members and element scores)

Redis ordered set (sorted set)