Redis-数据结构（字符串集合set）

Set和List类型不同的是，Set集合中不允许出现重复的元素

Set可包含的最大元素数量是4294967295

字符串集合（set）类型：

sadd 添加set元素

127.0.0.1:6379> sadd set1 a b c

(integer) 3

smembers 查看指定key集合元素

127.0.0.1:6379> smembers set1

1) "b"

2) "a"

3) "c"

srem 删除key集合中的元素

127.0.0.1:6379> smembers set1

1) "b"

2) "a"

3) "c"

4) "d"

5) "e"

127.0.0.1:6379> srem set1 a d

(integer) 2

127.0.0.1:6379> smembers set1

1) "b"

2) "e"

3) "c"

sismember 判断某个元素是否存在 返回1表示存在 返回0表示不存在

127.0.0.1:6379> smembers set1

1) "b"

2) "e"

3) "c"

127.0.0.1:6379> sismember set1 b

(integer) 1

127.0.0.1:6379> sismember set1 a

(integer) 0

sdiff 计算差集

127.0.0.1:6379> smembers set1

1) "b"

2) "e"

3) "c"

127.0.0.1:6379> smembers set2

1) "b"

2) "h"

3) "d"

4) "g"

5) "f"

6) "a"

7) "e"

8) "c"

127.0.0.1:6379> sdiff set2 set1

1) "f"

2) "g"

3) "h"

4) "d"

5) "a"

sinter 计算交集

127.0.0.1:6379> smembers set1

1) "b"

2) "e"

3) "c"

127.0.0.1:6379> smembers set2

1) "b"

2) "h"

3) "d"

4) "g"

5) "f"

6) "a"

7) "e"

8) "c"

127.0.0.1:6379> sinter set1 set2

1) "b"

2) "e"

3) "c"

sunion计算并集

127.0.0.1:6379> smembers set1

1) "b"

2) "e"

3) "c"

127.0.0.1:6379> smembers set2

1) "b"

2) "h"

3) "d"

4) "g"

5) "f"

6) "a"

7) "e"

8) "c"

127.0.0.1:6379> sunion set1 set2

1) "h"

2) "d"

3) "a"

4) "f"

5) "g"

6) "e"

7) "c"

8) "b"

scard 计算元素总数

127.0.0.1:6379> scard set1

(integer) 3

127.0.0.1:6379> scard set2

(integer) 8

srandmember 随机取一个或多个元素

127.0.0.1:6379> srandmember set1

"c"

127.0.0.1:6379> srandmember set1

"e"

127.0.0.1:6379> srandmember set1 2

1) "e"

2) "c"

sdiffstore 把差集结果存储到新集合中

127.0.0.1:6379> smembers set1

1) "b"

2) "e"

3) "c"

127.0.0.1:6379> smembers set2

1) "b"

2) "h"

3) "d"

4) "g"

5) "f"

6) "a"

7) "e"

8) "c"

127.0.0.1:6379> sdiffstore set3 set2 set1

(integer) 5

127.0.0.1:6379> smembers set3

1) "f"

2) "g"

3) "h"

4) "d"

5) "a"

sunionstore 把并集结果存储到新集合中

127.0.0.1:6379> smembers set3

1) "f"

2) "g"

3) "h"

4) "d"

5) "a"

127.0.0.1:6379> smembers set1

1) "b"

2) "e"

3) "c"

127.0.0.1:6379> sunionstore set4 set3 set1

(integer) 8

127.0.0.1:6379> smembers set4

1) "b"

2) "h"

3) "d"

4) "e"

5) "f"

6) "g"

7) "a"

8) "c"