Redis系列-存储篇set主要操作函数小结

        最近，总是以“太忙“为借口，很久没有blog了，凡事贵在恒，希望我能够坚持不懈，毕竟在blog的时候，也能提升自己。废话不说了，直奔主题”set“

redis set 是string类型对象的无序集合，set不管存储多少对象，对存储对象的add，remove和test操作的时间复杂度是O(1)。set最多能包含 2³² - 1 个member。

1、增加

语法：sadd key member[member...]

        解释：对特定key的set增加一个或多个值，返回是增加元素的个数。注意：对同一个member多次add，set中只会保留一份。

[root@xsf001 ~]# redis-cli
redis 127.0.0.1:6379> sadd stu zhangsan lisi wangwu #新增
(integer) 3
redis 127.0.0.1:6379> smembers stu    #得到set的所有member
1) "wangwu"
2) "lisi"
3) "zhangsan"
redis 127.0.0.1:6379> sadd stu zhangsan #增加存在的member
(integer) 0
redis 127.0.0.1:6379> smembers stu
1) "wangwu"
2) "lisi"
3) "zhangsan"
redis 127.0.0.1:6379> sadd tech wangwu liming joe
(integer) 3
redis 127.0.0.1:6379> sadd tech jim
(integer) 1
redis 127.0.0.1:6379> smembers tech
1) "jim"
2) "liming"
3) "wangwu"
4) "joe"

  2、查询

a）smembers

语法：smembers key

解释：获取set中的所有member

redis 127.0.0.1:6379> smembers stu
1) "wangwu"
2) "lisi"
3) "zhangsan"
redis 127.0.0.1:6379> smembers tech
1) "jim"
2) "liming"
3) "wangwu"
4) "joe"

b）sismember

语法：sismember key member

解释：判断值是否是set的member。如果值是set的member返回1，否则，返回0

redis 127.0.0.1:6379> sismember tech jim #jim 是set的member
(integer) 1
redis 127.0.0.1:6379> sismember tech jim001 #jim001 不是set的member
(integer) 0

c）scard

语法：scard key

解释：返回set的member个数，如果set不存在，返回0

redis 127.0.0.1:6379> scard tech  # tech 存在
(integer) 4
redis 127.0.0.1:6379> scard stud #stud 不存在
(integer) 0
redis 127.0.0.1:6379> scard stu
(integer) 4

d）srandmember

语法：srandmember key

解释：从set中返回一个随机member

redis 127.0.0.1:6379> srandmember stu
"zhangsan"
redis 127.0.0.1:6379> srandmember stu
"zhangsan"
redis 127.0.0.1:6379> srandmember stu
"wangwu"
redis 127.0.0.1:6379> srandmember stu
"zhangsan01"

3、删除

a）spop

语法：spop key

解释：移除并返回一个随机member

redis 127.0.0.1:6379> smembers stu #pop前
1) "zhangsan01"
2) "wangwu"
3) "lisi"
4) "zhangsan"
redis 127.0.0.1:6379> spop stu  #移除一个随机member
"lisi"
redis 127.0.0.1:6379> smembers stu #pop后
1) "zhangsan01"<span style="white-space:pre">   </span>
2) "wangwu"
3) "zhangsan"

b）srem

语法：srem key member [member ...]

解释：移除一个或多个member

redis 127.0.0.1:6379> smembers tech
1) "jim"
2) "liming"
3) "wangwu"
4) "joe"
redis 127.0.0.1:6379> srem tech jim   #移除jim
(integer) 1
redis 127.0.0.1:6379> smembers tech
1) "liming"
2) "wangwu"
3) "joe"
redis 127.0.0.1:6379> srem tech liming joe #移除多个member
(integer) 2
redis 127.0.0.1:6379> smembers tech
1) "wangwu"

c）smove

语法：smove source destination member

解释：将source中的member移动到destination

redis 127.0.0.1:6379> smembers tech   #smove前
1) "wangwu"
redis 127.0.0.1:6379> smembers stu
1) "zhangsan01"
2) "wangwu"
3) "zhangsan"
redis 127.0.0.1:6379> smove stu tech zhangsan  #将zhangsan 从stu移动到tech
(integer) 1
redis 127.0.0.1:6379> smembers stu #smove后
1) "zhangsan01"
2) "wangwu"
redis 127.0.0.1:6379> smembers tech
1) "wangwu"
2) "zhangsan"

4、其他

a）并集

语法：sunion key[key...]

解释：多个set的并集

redis 127.0.0.1:6379> smembers stu
1) "zhangsan01"
2) "wangwu"
redis 127.0.0.1:6379> sunion stu
1) "zhangsan01"
2) "wangwu"
redis 127.0.0.1:6379> smembers tech
1) "wangwu"
2) "zhangsan"
redis 127.0.0.1:6379> sunion stu tech
1) "zhangsan01"
2) "wangwu"
3) "zhangsan"

b）把并集结果存储到set

语法：sunionstore destination key [key ...]

解释：求多个set并集，并把结果存储到destination 

redis 127.0.0.1:6379> sunionstore same stu tech #把stu tech并集结果存储在union
(integer) 3
redis 127.0.0.1:6379> smembers union
1) "zhangsan01"
2) "wangwu"
3) "zhangsan"

 c）交集

语法：sinter key[key...]

解释：多个set的交集

redis 127.0.0.1:6379> smembers stu
1) "zhangsan01"
2) "wangwu"
redis 127.0.0.1:6379> smembers tech
1) "wangwu"
2) "zhangsan"
redis 127.0.0.1:6379> sinter stu tech
1) "wangwu"

d）把交集结果存储到指定set

语法：sinterstore destination key [key ...]

解释：把多个set的交集结果存储到destination 

redis 127.0.0.1:6379> sinterstore inter stu tech
(integer) 1
redis 127.0.0.1:6379> smembers inter
1) "wangwu"

      e) set中在其他set中不存在member

语法：sdiff key[key ...]

redis 127.0.0.1:6379>
redis 127.0.0.1:6379> smembers stu
1) "zhangsan01"
2) "wangwu"
redis 127.0.0.1:6379> smembers tech
1) "wangwu"
2) "zhangsan"
redis 127.0.0.1:6379> sdiff stu tech
1) "zhangsan01"
redis 127.0.0.1:6379> sdiff tech stu
1) "zhangsan"

f）把set中在其他set中不存在的member存储到新的set

语法：sdiffstore key[key...]

redis 127.0.0.1:6379> sdiffstore diff stu tech
(integer) 1
redis 127.0.0.1:6379> smembers diff
1) "zhangsan01"

主要参考：

http://redis.io/commands#set

http://redis.io/topics/data-types