sadd key member1 member2
scard key 获取集合元素个数
sdiff key1 key2 差集 key1-key2的差集 sdiff key1 key2 不等于 sdiff key2 key1
sdiffstore newkey ke1 key2 key1 - key2的差集，且保存到newkey中
smembers key 展示所有的元素
sismember key member 判断元素是否在key中
sinter key1 key2 交集
sinterstore newkey key1 key2
spop key 随机移除一个元素
srem key member 移除一个或者多个元素
sunion key1 key2 返回并集
sunionstore newkey key1 key2 并集存储到newkey
smove sourcekey desckey member 将member移到desckey
sscan key cursor match pattern