Home Database Mysql Tutorial Redis数据库(set类型和zset类型)

Redis数据库(set类型和zset类型)

Jun 07, 2016 pm 04:42 PM
redis database

set是一个集合,它是string类型的无序集合,set是通过hash table实现的,添加,删除,查找的时间复杂度都是O(1),对于集合我们可

一.set类型

set是一个集合,它是string类型的无序集合,,set是通过hash table实现的,添加,删除,查找的时间复杂度都是O(1),对于集合我们可以取并集,交集,差集。通过这些操作我们可以实现SNS中好友推荐和Blog的tag功能。

set常见操作:

(1)sadd

向一个集合中添加一个元素。例如:sadd set1 Hello

(2)smembers

查看集合中的所有元素。例如:smembers set1

(3)srem

删除集合中一个指定的元素。例如:srem set1 Hello

(4)spop

随机弹出set集合中德一个元素。例如:spop set1

(5)sdiff

求两个集合的差集,比如sdiff set1 set2,表示保留set1中与set2不同的所有元素。

(6)sdiffstore

将返回的差集存进一个集合。例如:sdiffstore set3 set1 set2,表示把set1与set2的差集存进

集合set3。

(7)sinter

返回给定两个集合的交集。例如:sinter set1 set2,表示返回set1和set2的交集。

(8)sinterstore

将两个集合的交集存进一个集合。例如:sinterstore set3 set1 set2,表示把set1和set2的交集

存进集合set3。

(9)sunion

返回给定两个集合的并集。例如:sunion set1 set2,表示返回set1和set2的并集。

(10)sunionstore

将两个集合的并集存进一个集合。例如:sunionstore set3 set1 set2,表示把set1和set2的并集

存进集合set3

(11)smove

从第一个key对应的set中移除member并添加到第二个对应的集合中。

例如:smove set1 set2 Hello,表示把set1中的Hello元素移动到set2中。

(12)scard

返回key对应集合的元素的个数。例如:scard set1。

(13)sismember

判断某一个元素是否为集合的元素。比如:sismember set1 Hello,表示判断Hello是否为set1的中

的元素。

(14)srandmember

随机返回名称为key的set的一个元素。例如:srandmember set1。

二.zset类型

zset是在set的基础上增加了顺序,形成一个有序的集合。

zset的常见操作:

(1)zadd

向有序集合zset中增加一个元素。例如:zadd zset 1 Hello

(2)zrange

输出zset中指定范围内的的所有元素,按照score从小到大的顺序。

例如:zrange zset 0 -1 withscores,表示输出有序集合zset中所有的元素,并且输出顺序号。

(3)zrem

删除名称为key的zset集合中的元素member。例如:zrem set1 Hello。

(4)zincrby

把有序集合zset中的指定元素的序列号加上指定的值。例如:zincrby zset 4 Hello

(5)zrank

返回名称为key的zset集合中元素的排名,按照下标从小到大的排名。例如:zrank zset Hello。

(6)zrevrank

返回名称为key的zset集合中元素的排名,按照下表从大到小的排名。例如:zrevrank zset Hello。

(7)zrevrange

按照score从大到小的顺序输出集合中所有元素。例如:zrevrange zset 0 -1 withscores。

(8)zrangebyscore

返回集合中给定区间的元素。例如:zrangebyscore zset 2 3 withscores

(9)zcount

返回集合中score在给定区间的数量。zcount zset 2 3

(10)zcard

返回集合中元素的个数。

(11)zremrangebyrank

按照索引来删除给定区间的元素。例如:zremrangebyrank zset 1 2

(12)zremrangebyscore

删除score在指定范围内的元素。例如:zremrangebyscore zset 1 2

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