有序集合

有序集合支持交集、并集合、差集合。初看可选选项不知什么意思[AGGREGATE SUM|MIN|MAX] ，其实就是在执行聚合时，如果member一样但是socre 不一致时应该选择哪个score作为聚合后的值。

ZUNION numkeys key [key ...] [WEIGHTS weight [weight ...]] [AGGREGATE SUM|MIN|MAX] [WITHSCORES]

ZINTER numkeys key [key ...] [WEIGHTS weight [weight ...]] [AGGREGATE SUM|MIN|MAX] [WITHSCORES]

ZDIFF numkeys key [key ...] [WITHSCORES]

接下来做一个测试验证:

127.0.0.1:6379> FLUSHALL
OK
127.0.0.1:6379> 
127.0.0.1:6379> ZADD mysorted nx 100 a 99 b
(integer) 2
127.0.0.1:6379> ZADD mysorted1 nx 99 a 99 b

127.0.0.1:6379> ZUNION 2 mysorted mysorted1 WITHSCORES
1) "b"
2) "198"
3) "a"
4) "199"
127.0.0.1:6379> ZUNION 2 mysorted mysorted1 WITHSCORES AGGREGATE MIN
1) "a"
2) "99"
3) "b"
4) "99