1. order set有序集合类型的操作（有序集合）
有序集合是在无序集合的基础上加了一个排序的依据，这个排序依据叫score，因此声明一个集合为有序集合的时候要加上score（作为排序的依据）
1.1. zadd key [NX|XX] [CH] [INCR] score member [score member ...]
语法：zadd key [NX|XX] [CH] [INCR] score member [score member ...]
作用：添加元素
例：
127.0.0.1:6379> zadd age 21 lily 22 tom 19 poly 15 wang
(integer) 4
1.2. zrange key start stop [WITHSCORES]
语法：zrange key start stop [WITHSCORES]
作用：把集合排序后（默认是升序排列），返回排序名次[start,stop]的元素（排序名次从0开始）
Withscores 是把score也打印出来
注：zrange key 0 -1 #返回所有排序的元素，默认升序
例：
127.0.0.1:6379> zadd age 21 lily 22 tom 19 poly 15 wang
(integer) 4
127.0.0.1:6379> zrange age 0 2
1) "wang"
2) "poly"
3) "lily"
127.0.0.1:6379> zrange age 0 -1 #查询所有的元素，默认升序
1) "wang"
2) "poly"
3) "lily"
4) "tom"
127.0.0.1:6379> zrange age 0 2 withscores
1) "wang"
2) "15"
3) "poly"
4) "19"
5) "lily"
6) "21"
127.0.0.1:6379> zrange age 0 -1 withscores
1) "wang"
2) "15"
3) "poly"
4) "19"
5) "lily"
6) "21"
7) "tom"
8) "22"
1.3. zrevrange key start stop [WITHSCORES]
语法：zrevrange key start stop [WITHSCORES]
作用：把集合降序排列，取排序名次[start,stop]之间的元素
例：
127.0.0.1:6379> zadd age 20 li 22 wu 25 wang 30 zhao
(integer) 4
127.0.0.1:6379> zrevrange age 0 -1 withscores
1) "zhao"
2) "30"
3) "wang"
4) "25"
5) "wu"
6) "22"
7) "li"
8) "20"
127.0.0.1:6379> zrevrange age 1 2 withscores
1) "wang"
2) "25"
3) "wu"
4) "22"
1.4. zrangebyscore key min max [WITHSCORES] [LIMIT offset count]
语法：zrangebyscore key min max [WITHSCORES] [LIMIT offset count]
作用：集合（升序）排序后，取score在[min,max]内的元素，并跳过offset个，取出count个
例：
127.0.0.1:6379> zrangebyscore age 14 20
1) "wang"
2) "poly"
127.0.0.1:6379> zrangebyscore age 14 20
1) "wang"
2) "poly"
127.0.0.1:6379> zrangebyscore age 14 20 withscores
1) "wang"
2) "15"
3) "poly"
4) "19"
127.0.0.1:6379> zrangebyscore age 14 20 withscores limit 1 2
1) "poly"
2) "19"
127.0.0.1:6379> zrangebyscore age 14 22 withscores
1) "wang"
2) "15"
3) "poly"
4) "19"
5) "lily"
6) "21"
7) "tom"
8) "22"
127.0.0.1:6379> zrangebyscore age 14 22 withscores limit 1 2
1) "poly"
2) "19"
3) "lily"
4) "21"
1.5. zrank key member
语法：zrank key member
作用：查询member的排名（升序，从 0名开始）
返回值：存在返回member的排名（升序，从0开始）；不存在返回nil
例：
127.0.0.1:6379> zrange age 0 -1 withscores
1) "wang"
2) "15"
3) "poly"
4) "19"
5) "lily"
6) "21"
7) "tom"
8) "22"
127.0.0.1:6379> zrank age poly
(integer) 1
127.0.0.1:6379> zrank age wang
(integer) 0
127.0.0.1:6379> zrank age tom
(integer) 3
127.0.0.1:6379> zrank age haha
(nil)
1.6. zrevrank key member
语法：zrevrank key member
作用：查询member的排名（降序，从0名开始）
返回值：存在返回member的排名（降序，从0开始）；不存在返回nil
例：
127.0.0.1:6379> zrevrank age wang
(integer) 3
127.0.0.1:6379> zrevrank age poly
(integer) 2
127.0.0.1:6379> zrevrank age tom
(integer) 0
1.7. zrem key member [member ...]
语法：zrem key member [member ...]
作用：删除集合中的元素member [member ...]
返回值：返回真正删除掉的元素的个数
例：
127.0.0.1:6379> zrange age 0 -1 withscores
1) "wang"
2) "15"
3) "poly"
4) "19"
5) "lily"
6) "21"
7) "tom"
8) "22"
127.0.0.1:6379> zrem age wang
(integer) 1
127.0.0.1:6379> zrange age 0 -1 withscores
1) "poly"
2) "19"
3) "lily"
4) "21"
5) "tom"
6) "22"
127.0.0.1:6379> zrem age poly lily haha
(integer) 2
127.0.0.1:6379> zrange age 0 -1 withscores
1) "tom"
2) "22"
1.8. zremrangebyscore key min max
语法：zremrangebyscore key min max
作用：按照score来删除元素，删除score在[min,max]之间的元素
返回值：返回真正删除元素的个数
例：
127.0.0.1:6379> zrange age 0 -1 withscores
1) "wang"
2) "15"
3) "poly"
4) "19"
5) "lily"
6) "21"
7) "tom"
8) "22"
127.0.0.1:6379> zremrangebyscore age 15 20
(integer) 2
127.0.0.1:6379> zrange age 0 -1 withscores
1) "lily"
2) "21"
3) "tom"
4) "22"
1.9. zremrangebyrank key start stop
语法：zremrangebyrank key start stop
作用：按排名删除元素，删除名次在[start,end]之间的元素（默认升序）
返回值：返回真正删除元素的个数
例：
127.0.0.1:6379> zrange age 0 -1 withscores
1) "wang"
2) "15"
3) "poly"
4) "19"
5) "lily"
6) "21"
7) "tom"
8) "22"
127.0.0.1:6379> zremrangebyrank age 0 1
(integer) 2
127.0.0.1:6379> zrange age 0 -1 withscores
1) "lily"
2) "21"
3) "tom"
4) "22"
1.10. zcard key
语法：zcard key
作用：返回集合中所有元素的个数
例：
127.0.0.1:6379> zadd age 20 li 22 wu 25 wang 30 zhao
(integer) 4
127.0.0.1:6379> zcard age
(integer) 4