Redis系列-存储篇sorted set主要操作函数小结
redis支持有序集合，即sorted set。sorted set在set的基础上，增加了排序属性，是set的升级版。这里简要谈谈sorted set的常用函数：
1)insert www.zzzyk.com
a） zadd
语法：zadd key score member [[score member] [score member] ...]
解释：增加一个或多个member【根据score排序】到有序集key中，如果member已经存在，只更新score。返回增加member个数，不包含已经存在的member
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[root@xsf001 ~]# redis-cli
redis 127.0.0.1:6379> ZADD score 230 zhangsan
(integer) 1
redis 127.0.0.1:6379> zadd score 240 lisi 250 wangwu
(integer) 2
redis 127.0.0.1:6379> zadd score 100 liuli
redis 127.0.0.1:6379> zadd score 249 wangwu
(integer) 0
注意：有些redis版本，只能一次添加一个member
2）select
a）zrange
语法：zrange key start stop [withscores]
解释：返回有续集key中指定范围【通过索引 start stop】的member[及其score]；
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redis 127.0.0.1:6379> zrange score 0 -1 #所有元素
1) "liuli"
2) "zhangsan"
3) "lisi"
4) "wangwu"
redis 127.0.0.1:6379> zrange score 0 -1 withscores #所有member及score
1) "liuli"
2) "100"
3) "zhangsan"
4) "230"
5) "lisi"
6) "240"
7) "wangwu"
8) "249"
redis 127.0.0.1:6379> zrange score 0 2 withscores #前三个元素
1) "liuli"
2) "100"
3) "zhangsan"
4) "230"
5) "lisi"
6) "240"
redis 127.0.0.1:6379> zrange score 0 -2 #第一个元素到
1) "liuli"
2) "zhangsan"
3) "lisi"
注意：0，表示第一个元素，-1 表示最后一个元素，-2 表示倒数第二个元素
b）zcount
语法：zcount key min max
解释：统计key中score值介于min 和max之间的member个数
[plain]
redis 127.0.0.1:6379> zrange score 0 -1 withscores
1) "liuli"
2) "100"
3) "zhangsan"
4) "230"
5) "lisi"
6) "240"
7) "wangwu"
8) "249"
redis 127.0.0.1:6379> zcount score 230 240 # count（score >=230 && score <=240）
(integer) 2
c) zscore
语法：zscore key member
解释：返回有续集key中member的score
[plain]
redis 127.0.0.1:6379> zscore score liuli
"100"
d）zrevrange
语法：zrevrange key start stop [withscores]
解释：返回有续集key中指定范围[通过索引start stop]的member[及score]，返回member根据score按降序排列
[plain]
redis 127.0.0.1:6379> zrevrange score 0 -1 withscores
1) "wangwu"
2) "249"
3) "lisi"
4) "240"
5) "zhangsan"
6) "230"
7) "liuli"
8) "100"
redis 127.0.0.1:6379> zrevrange score 1 -2
1) "lisi"
2) "zhangsan"
注意：索引0 表示第一个元素，-1 最后一个元素，-2 倒数第二个元素；依次类推
e）zrangebyscore
语法：zrangebyscore key min max [withscores] [limit offset count]
解释：返回有续集key中，score大于等于min并且小于等于max的member。返回结果按照score递增的次序排列。可选withscores决定返回结果集中仅仅返回member还是返回member和score；可选参数limit 指定返回结果的数量区间。
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redis 127.0.0.1:6379> zrangebyscore score 100 10000 withscores
1) "liuli"
2) "100"
3) "zhangsan"
4) "230"
5) "lisi"
6) "240"
7) "wangwu"
8) "249"
redis 127.0.0.1:6379> zrangebyscore score 100 10000 limit 1 3
1) "zhangsan"
2) "lisi"
3) "wangwu"
f）zrevrangebyscore
语法：zrevrangescore key max min [withscores] [limit offset count]
解释：返回有续集key中score<=max并且score>=min 的元素，返回结果根据score从大到小顺序排列。可选参数withscores决定结果集中是否包含score，可选参数limit 指定返回结果集范围。
[plain]
redis 127.0.0.1:6379> zrevrangebyscore score 0 10000
(empty list or set)
redis 127.0.0.1:6379> zrevrangebyscore score 10000 0
1) "wangwu"
2) "lisi"
3) "zhangsan"
4) "liuli"
redis 127.0.0.1:6379> zrevrangebyscore score 10000 0 withscores limit 0, 2
1) "wangwu"
2) "249"
3) "lisi"
4) "240"
注意：max在min之前
g）zrank
语法：zrank key member
解释：根据score从低到高，返回member在有续集中的index
[plain]
redis 127.0.0.1:6379> zrange score 0 -1
1) "liuli"
2) "zhangsan"
3) "lisi"
4) "wangwu"
redis 127.0.0.1:6379> zrank score liuli
(integer) 0
redis 127.0.0.1:6379> zrank score wangwu
(integer) 3
h）zrevrank
语法：zrevrank key member
解释：根据score从高到低排序，返回member在有序集key中的index
[plain]
redis 127.0.0.1:6379> zrange score 0 -1
1) "liuli"
2) "zhangsan"
3) "lisi"
4) "wangwu"
redis 127.0.0.1:6379> zrevrank score liuli
(integer) 3
redis 127.0.0.1:6379> zrevrank score wangwu
(integer) 0
i)zcard
语法：zcard key
解释：返回有续集key的基数
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redis 127.0.0.1:6379> zcard score
(integer) 4
redis 127.0.0.1:6379> zcard stdu #有续集不存在返回0
(integer) 0
3）update
a）zincrby
语法：zincrby key increment member
解释：有续集key的member增加增量increment，返回增加后的score
[plain]
redis 127.0.0.1:6379> zscore score liuli
"100"
