redis 五大数据类型--集合

set（集合）

set中的值是不能重复的。

127.0.0.1:6379> sadd myset one  #向set集合中添加值
(integer) 1
127.0.0.1:6379> sadd myset two thre four
(integer) 3
127.0.0.1:6379> smembers myset  #获取指定set的所有值
1) "one"
2) "four"
3) "two"
4) "thre"
127.0.0.1:6379> sismember myset one  #判断一个值是否存在set集合中
(integer) 1
127.0.0.1:6379> sismember myset six
(integer) 0
127.0.0.1:6379> scard myset  #获取set集合中的内容元素个数
(integer) 4

127.0.0.1:6379> srem myset one   #移除set集合中指定的元素
(integer) 1
127.0.0.1:6379> smembers myset
1) "four"
2) "two"
3) "thre"
127.0.0.1:6379> srem myset two
(integer) 1
127.0.0.1:6379> smembers myset
1) "four"
2) "thre"

#set 是无序不重复集合
127.0.0.1:6379> sadd myset one two three four five
(integer) 5
127.0.0.1:6379> smembers myset
1) "one"
2) "four"
3) "two"
4) "three"
5) "five"
127.0.0.1:6379> srandmember myset  #随机抽取一个值
"five"
127.0.0.1:6379> srandmember myset
"two"
127.0.0.1:6379> srandmember myset 2 #指定数量，随机抽取指定个数的值
1) "four"
2) "five"
127.0.0.1:6379> srandmember myset 2
1) "four"
2) "three"

127.0.0.1:6379> smembers myset
1) "three"
2) "four"
3) "one"
4) "two"
5) "five"
127.0.0.1:6379> spop myset   #随机删除一个值
"four"
127.0.0.1:6379> smembers myset
1) "one"
2) "two"
3) "five"
4) "three"
127.0.0.1:6379> spop myset
"five"
127.0.0.1:6379> smembers myset
1) "one"
2) "two"
3) "three"

127.0.0.1:6379> sadd myset1 one two three four
(integer) 4
127.0.0.1:6379> sadd myset2 1 2 3 4
(integer) 4
127.0.0.1:6379> smembers myset1
1) "one"
2) "four"
3) "two"
4) "three"
127.0.0.1:6379> smembers myset2
1) "1"
2) "2"
3) "3"
4) "4"
127.0.0.1:6379> smove myset1 myset2 one  #将myset1集合的one元素移动到myset2中
(integer) 1
127.0.0.1:6379> smembers myset1
1) "four"
2) "two"
3) "three"
127.0.0.1:6379> smembers myset2
1) "2"
2) "3"
3) "4"
4) "1"
5) "one"

127.0.0.1:6379> sadd myset1 a b c d e
(integer) 5
127.0.0.1:6379> sadd myset2 d e f g
(integer) 4
127.0.0.1:6379> smembers myset1
1) "a"
2) "b"
3) "d"
4) "c"
5) "e"
127.0.0.1:6379> smembers myset2
1) "e"
2) "f"
3) "g"
4) "d"
127.0.0.1:6379> sdiff myset1 myset2  #差集
1) "a"
2) "b"
3) "c"
127.0.0.1:6379> sinter myset1 myset2  #交集
1) "e"
2) "d"
127.0.0.1:6379> sunion myset1 myset2  #并集
1) "a"
2) "e"
3) "f"
4) "g"
5) "c"
6) "b"
7) "d"

 微博，A用户将所有关注的人放在一个set集合中，将他的粉丝放在另一个集合中。共同关注，共同爱好，二度好友，推荐好友。