ZUNION

Usage:
ZUNION numkeys key [ key ... ] [ WEIGHTS weight ] [ [ WEIGHTS weight ] ... ] [ AGGREGATE sum | min | max ] [ withscores ]
Complexity:
O(N)+O(M*log(M)) with N being the sum of the sizes of the input sorted sets, and M being the number of elements in the resulting sorted set.
Since:
6.2.0

This command is similar to ZUNIONSTORE, but instead of storing the resulting sorted set, it is returned to the client.

For a description of the WEIGHTS and AGGREGATE options, see ZUNIONSTORE.

Examples

127.0.0.1:6379> ZADD zset1 1 "one"
(integer) 1
127.0.0.1:6379> ZADD zset1 2 "two"
(integer) 1
127.0.0.1:6379> ZADD zset2 1 "one"
(integer) 1
127.0.0.1:6379> ZADD zset2 2 "two"
(integer) 1
127.0.0.1:6379> ZADD zset2 3 "three"
(integer) 1
127.0.0.1:6379> ZUNION 2 zset1 zset2
1) "one"
2) "three"
3) "two"
127.0.0.1:6379> ZUNION 2 zset1 zset2 WITHSCORES
1) "one"
2) "2"
3) "three"
4) "3"
5) "two"
6) "4"