Redis 評(píng)分的聚合

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"

一個(gè)小技巧是如果需要對(duì)評(píng)分進(jìn)行倍加，則使用如下的方法：

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"