005_ redis_ Set set

005_redis_set aggregate

1、Redis Medium Set Structure and Java Medium HashSet similar , It can be seen as value by null Of HashMap. Because it is also a hash surface , Therefore, it also has the ability to HashSet Similar features .

• Element disorder
• Element is not repeatable
• Quick search
• Support intersection 、 Combine 、 Difference set and other functions

2、Set Collect common commands

• SADD： Add one or more elements to the collection
• SREM： remove Set The specified element in
• SCARD: return Set The number of elements in
• SISMEMBER: Determine whether an element exists in Set in
• SMEMBERS： obtain Set All elements in
• SINTER： seek key1 And key2 Intersection
• SDIFF： seek key1 And key2 The difference between the set
• SUNION： seek key1 And key2 Union

（2） Related exercises

127.0.0.1:6379> sadd zs lisi wangwu zhaoliu
(integer) 3
127.0.0.1:6379> sadd lisi wangwu mazi ergou
(integer) 3
127.0.0.1:6379> SCARD zs
(integer) 3
127.0.0.1:6379> SINTER zs lisi
1) "wangwu"
127.0.0.1:6379> SDIFF zs lisi
1) "lisi"
2) "zhaoliu"
127.0.0.1:6379> SUNION zs lisi
1) "ergou"
2) "wangwu"
3) "zhaoliu"
4) "mazi"
5) "lisi"
127.0.0.1:6379> SISMENBER zs lisi
(error) ERR unknown command `SISMENBER`, with args beginning with: `zs`, `lisi`, 
127.0.0.1:6379> SISmember zs lisi
(integer) 1
127.0.0.1:6379> SREM zs lisi
(integer) 1
127.0.0.1:6379> smembers zs
1) "wangwu"
2) "zhaoliu"