ZUNIONSTORE destination numkeys key [key ...] [WEIGHTS weight] [AGGREGATE SUM|MIN|MAX] 例如：
127.0.0.1:6379> zrangebyscore votes -inf inf withscores 1) "sina" 2) "1" 3) "google" 4) "5" 5) "baidu" 6) "10" 127.0.0.1:6379> zrangebyscore visits -inf inf withscores 1) "baidu" 2) "1" 3) "google" 4) "5" 5) "sina" 6) "10" 127.0.0.1:6379> zunionstore award 2 visits votes weights 1 2 aggregate sum (integer) 3 127.0.0.1:6379> zrangebyscore award -inf inf withscores 1) "sina" 2) "12" 3) "google" 4) "15" 5) "baidu" 6) "21" 一个小技巧是如果需要对评分进行倍加，则使用如下的方法：
127.0.0.1:6379>zrangebyscore visits -inf inf withscores 1) "baidu" 2) "1" 3) "google" 4) "5" 5) "sina" 6) "10" 127.0.0.1:6379>zunionstore visits 1 visits weights 2 (integer) 3 127.0.0.1:6379>zrangebyscore visits -inf inf withscores 1) "baidu" 2) "2" 3) "google" 4) "10" 5) "sina" 6) "20"