--- Set: 无序不重复集合 ---
1. 基础操作
添加标签
SADD article:1:tags "tech" "redis" "database"
SADD article:2:tags "tech" "mysql" "database"
尝试添加重复元素 (无效)
SADD article:1:tags "redis"
查看所有元素
SMEMBERS article:1:tags
判断元素是否存在
SISMEMBER article:1:tags "python"
2. 集合运算
交集 (Intersection): 找出两篇文章共同的标签
SINTER article:1:tags article:2:tags
结果: "tech", "database"
并集 (Union): 所有涉及的标签
SUNION article:1:tags article:2:tags
差集 (Difference): article:1 有但 article:2 没有的
SDIFF article:1:tags article:2:tags
结果: "redis"
bash
127.0.0.1:6379> SADD article:1:tags "tech" "redis" "database"
(integer) 3
127.0.0.1:6379> SADD article:2:tags "tech" "mysql" "database"
(integer) 3
127.0.0.1:6379> SADD article:1:tags "redis"
(integer) 0
127.0.0.1:6379> SMEMBERS article:1:tags
1) "tech"
2) "redis"
3) "database"
127.0.0.1:6379> SISMEMBER article:1:tags "python"
(integer) 0
127.0.0.1:6379> SINTER article:1:tags article:2:tags
1) "tech"
2) "database"
127.0.0.1:6379> SUNION article:1:tags article:2:tags
1) "tech"
2) "mysql"
3) "database"
4) "redis"
127.0.0.1:6379> SDIFF article:1:tags article:2:tags
1) "redis"