【Redis】集合类型Set 常用命令详解

1. sadd - 添加

语法：sadd key value

> sadd testset A
1
> sadd testset B
1
> sadd testset C
1
> sadd testset C # set的值不能重复
0
> smembers set1 # 查询指定set的所有值，乱序
1) "B"
2) "A"
3) "C"

2. 获取

2.1 smembers - 获取set集合中的所有元素

语法：smembers key

> smembers testset # 查询指定set的所有值，乱序
1) "B"
2) "A"
3) "C"

2.2 scard - 获取元素的个数

语法：scard set

> scard set1
3

2.3 srandmember - 随机获取元素

语法：srandmember set [num]

• 默认获取一个随机元素，后跟数字，代表随机获取几个元素

> smembers testset
1) "D"
2) "B"
3) "A"
4) "C"> srandmember testset # 获取一个随机元素
"D"> srandmember testset # 获取一个随机元素
"A"> srandmember testset 2 # 获取两个随机元素
1) "B"
2) "D"

3. 删除

3.1 srem - 删除set集合中某元素

语法: srem key value

> smembers testset 
1) "B"
2) "A"
3) "C"> srem testset C
1> smembers testset
1) "B"
2) "A"

3.2 spop - 随机删除一个元素

语法：spop set

> smembers testset
1) "D"
2) "B"
3) "A"
4) "C"> spop testset # 随机删除一个元素
"A"> spop testset # 随机删除一个元素
"B"> smembers testset
1) "D"
2) "C"

4. smove - 移动指定值到另一个set

语法：smove set1 set2 value

> smembers testset
1) "D"
2) "C"> smove testset testset1 D # 从 testset 移动 D 到 testset1
1> smembers testset
1) "C"> smembers testset1
1) "D"

5. sinter - 交集 sunion - 并集 sdiff - 差集

sinter set1 set2：交集

sunion set1 set2：并集

sdiff set1 set2：差集

> sadd testset A
1
> sadd testset B
1
> sadd testset C
1> sadd testset1 B
1
> sadd testset1 C
1
> sadd testset1 D
1
> sadd testset1 E
1> sinter testset testset1 # 交集
1) "B"
2) "C"> sunion testset testset1 # 并集
1) "D"
2) "E"
3) "C"
4) "B"
5) "A"> sdiff testset testset1 # 差集
1) "A"