Redis系列-存储篇set主要操作函数小结
最近,总是以“太忙“为借口,很久没有blog了,凡事贵在恒,希望我能够坚持不懈,毕竟在blog的时候,也能提升自己。废话不说了,直奔主题”set“
redis set 是string类型对象的无序集合,set不管存储多少对象,对存储对象的add,remove和test操作的时间复杂度是O(1)。set最多能包含 232 - 1 个member。
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1、增加
语法:sadd key member[member...]
解释:对特定key的set增加一个或多个值,返回是增加元素的个数。注意:对同一个member多次add,set中只会保留一份。 www.zzzyk.com
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[root@xsf001 ~]# redis-cli
redis 127.0.0.1:6379> sadd stu zhangsan lisi wangwu #新增
(integer) 3
redis 127.0.0.1:6379> smembers stu #得到set的所有member
1) "wangwu"
2) "lisi"
3) "zhangsan"
redis 127.0.0.1:6379> sadd stu zhangsan #增加存在的member
(integer) 0
redis 127.0.0.1:6379> smembers stu
1) "wangwu"
2) "lisi"
3) "zhangsan"
redis 127.0.0.1:6379> sadd tech wangwu liming joe
(integer) 3
redis 127.0.0.1:6379> sadd tech jim
(integer) 1
redis 127.0.0.1:6379> smembers tech
1) "jim"
2) "liming"
3) "wangwu"
4) "joe"
2、查询
a)smembers
语法:smembers key
解释:获取set中的所有member
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redis 127.0.0.1:6379> smembers stu
1) "wangwu"
2) "lisi"
3) "zhangsan"
redis 127.0.0.1:6379> smembers tech
1) "jim"
2) "liming"
3) "wangwu"
4) "joe"
b)sismember
语法:sismember key member
解释:判断值是否是set的member。如果值是set的member返回1,否则,返回0
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redis 127.0.0.1:6379> sismember tech jim #jim 是set的member
(integer) 1
redis 127.0.0.1:6379> sismember tech jim001 #jim001 不是set的member
(integer) 0
c)scard
语法:scard key
解释:返回set的member个数,如果set不存在,返回0
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redis 127.0.0.1:6379> scard tech # tech 存在
(integer) 4
redis 127.0.0.1:6379> scard stud #stud 不存在
(integer) 0
redis 127.0.0.1:6379> scard stu
(integer) 4
d)srandmember
语法:srandmember key
解释:从set中返回一个随机member
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redis 127.0.0.1:6379> srandmember stu
"zhangsan"
redis 127.0.0.1:6379> srandmember stu
"zhangsan"
redis 127.0.0.1:6379> srandmember stu
"wangwu"
redis 127.0.0.1:6379> srandmember stu
"zhangsan01"
3、删除
a)spop
语法:spop key
解释:移除并返回一个随机member
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redis 127.0.0.1:6379> smembers stu #pop前
1) "zhangsan01"
2) "wangwu"
3) "lisi"
4) "zhangsan"
redis 127.0.0.1:6379> spop stu #移除一个随机member
"lisi"
redis 127.0.0.1:6379> smembers stu #pop后
1) "zhangsan01"<span style="white-space:pre"> </span>
2) "wangwu"
3) "zhangsan"
b)srem
语法:srem key member [member ...]
解释:移除一个或多个member
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redis 127.0.0.1:6379> smembers tech
1) "jim"
2) "liming"
3) "wangwu"
4) "joe"
redis 127.0.0.1:6379> srem tech jim #移除jim
(integer) 1
redis 127.0.0.1:6379> smembers tech
1) "liming"
2) "wangwu"
3) "joe"
redis 127.0.0.1:6379> srem tech liming joe #移除多个member
(integer) 2
redis 127.0.0.1:6379> smembers tech
1) "wangwu"
c)smove
语法:smove source destination member
解释:将source中的member移动到destination
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redis 127.0.0.1:6379> smembers tech #smove前
1) "wangwu"
redis 127.0.0.1:6379> smembers stu
1) "zhangsan01"
2) "wangwu"
3) "zhangsan"
redis 127.0.0.1:6379> smove stu tech zhangsan #将zhangsan 从stu移动到tech
(integer) 1
redis 127.0.0.1:6379> smembers stu #smove后
1) "zhangsan01"
2) "wangwu"
redis 127.0.0.1:6379> smembers tech
1) "wangwu"
2) "zhangsan"
4、其他
a)并集
语法:sunion key[key...]
解释:多个set的并集
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redis 127.0.0.1:6379> smembers stu
1) "zhangsan01"
2) "wangwu"
redis 127.0.0.1:6379> sunion stu
1) "zhangsan01"
2) "wangwu"
redis 127.0.0.1:6379> smembers tech
1) "wangwu"
2) "zhangsan"
redis 127.0.0.1:6379> sunion stu tech
1) "zhangsan01"
2) "wangwu"
3) "zhangsan"
b)把并集结果存储到set
语法:sunionstore destination key [key ...]
解释:求多个set并集,并把结果存储到destination
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redis 127.0.0.1:6379> sunionstore same stu tech #把stu tech并集结果存储在union
(integer) 3
redis 127.0.0.1:6379> smembers union
1) "zhangsan01"
2) "wangwu"
3) "zhangsan"
c)交集
语法:sinter key[key...]
解释:多个set的交集
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