Redis Zunionstore Command

Redis Sorted Sets (sorted set)

The Redis Zunionstore command calculates the union of one or more sorted sets given, where the number of keys given must be specified by the numkeys parameter, and stores the union (result set) into destination.

By default, the score value of a member in the result set is the sum of the score values of the member under all given sets.

Syntax

The basic syntax of the redis Zunionstore command is as follows:

redis 127.0.0.1:6379> ZUNIONSTORE destination numkeys key [key ...] [WEIGHTS weight [weight ...]] [AGGREGATE SUM|MIN|MAX]

Available Version

>= 2.0.0

Return Value

The number of members in the result set saved to destination.

redis> ZADD zset1 1 "one"

(integer) 1

redis> ZADD zset1 2 "two"

(integer) 1

redis> ZADD zset2 1 "one"

(integer) 1

redis> ZADD zset2 2 "two"

(integer) 1

redis> ZADD zset2 3 "three"

(integer) 1

redis> ZUNIONSTORE out 2 zset1 zset2 WEIGHTS 2 3

(integer) 3

redis> ZRANGE out 0 -1 WITHSCORES

1) "one"

2) "5"

3) "three"

4) "9"

5) "two"

6) "10"

redis> 

Redis Sorted Sets (sorted set)