ZUNION
ZUNION numkeys key [key ...] [WEIGHTS weight [weight ...]] [AGGREGATE SUM|MIN|MAX] [WITHSCORES]
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.
Return value
Array reply: the result of union (optionally with their scores, in case the WITHSCORES option is given).
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>  ZUNION 2 zset1 zset2 1) "one"
2) "three"
3) "two" redis>  ZUNION 2 zset1 zset2 WITHSCORES 1) "one"
2) "2"
3) "three"
4) "3"
5) "two"
6) "4"
    © 2009–2020 Salvatore Sanfilippo
Licensed under the Creative Commons Attribution-ShareAlike License 4.0.
    https://redis.io/commands/zunion