Redis Zunionstore Command

Redis Ordered Set (sorted set)

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

By default, the score value of a member in the result set is the sum of the score values of that member across 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 Versions

>= 2.0.0

Return Value

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

Examples

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 Ordered Set (sorted set)

Other Extensions