Redis中key相关主要操作函数

总结redis中跟key相关的常用函数
1)keys
语法:keys pattern
解释:查找所有匹配指定模式pattern的key
[root@cjlx ~]# redis-cli   
redis 127.0.0.1:6379> keys * #所有key
1) "score"
2) "stu"
3) "score1"
4) "dest"
5) "lst.user"
6) "lst.tect"
redis 127.0.0.1:6379> keys scor?
1) "score"
redis 127.0.0.1:6379> keys scor[ee1]
1) "score"
2)randomkey
语法:randomkey 
解释:返回一个随机key
redis 127.0.0.1:6379> randomkey  
"score"
redis 127.0.0.1:6379> randomkey
"list.user"
3)exists
语法:exists key
解释:判断一个key是否存在
redis 127.0.0.1:6379> exists score  #key存在 返回1  
(integer) 1
redis 127.0.0.1:6379> exists scorefda #key不存在 返回0
(integer) 0
4)type
语法:type key
解释:返回key所存储的值类型,返回值:none [key不存在],string,list ,set, zset和hash
redis 127.0.0.1:6379> type score  
zset
redis 127.0.0.1:6379> type lst.user
list
5)expire
语法:expire key seconds
解释:设置key的生存时间,单位是秒,当key过期时,会被自动删除
redis 127.0.0.1:6379> expire dest 30  
(integer) 1
redis 127.0.0.1:6379> expire dest1 30 # key不存在
(integer) 0
6)ttl
语法: ttl key
解释:得到key能存活时间,如果key不存在或没有设置生存时间时,返回-1
redis 127.0.0.1:6379> expire diff 100  
(integer) 1
redis 127.0.0.1:6379> ttl diff
(integer) 94
redis 127.0.0.1:6379> ttl diff
(integer) 92

7)persist
语法:persist key
解释:移除给定key的生存时间
redis 127.0.0.1:6379> ttl diff  
(integer) 28
redis 127.0.0.1:6379> persist diff
(integer) 1
redis 127.0.0.1:6379> ttl diff
(integer) -1
8)rename
语法:rename key newkey
解释:将key改名为newkey
redis 127.0.0.1:6379> smembers diff  
1) "zhangsan01"
redis 127.0.0.1:6379> rename diff diff01
OK
redis 127.0.0.1:6379> smembers diff
(empty list or set)
redis 127.0.0.1:6379> smembers diff01
1) "zhangsan01"
redis 127.0.0.1:6379> rename diff diff01
(error) ERR no such key
注意:当key和newkey相同或key不存在时,返回错误;当newkey已存在时,rename将覆盖旧值。
 
9)renamenx
语法:renamenx key newkey
解释:当且仅当newkey不存在时,改名key
redis 127.0.0.1:6379> renamenx diff01 stu  #stu存在  
(integer) 0
redis 127.0.0.1:6379> renamenx diff01 diff #diff不存在
(integer) 1
10)del
语法:del key [key ...]
解释:删除一个或多个key
redis 127.0.0.1:6379> del score1  
(integer) 1
redis 127.0.0.1:6379> del union diff aa #key aa 不存在
(integer) 2
11)move
语法:move key db
解释:将key移动到指定db
redis 127.0.0.1:6379> smembers stu #默认0  
1) "zhangsan01"
2) "wangwu"
redis 127.0.0.1:6379> move stu 1 #移动到 1
(integer) 1
redis 127.0.0.1:6379> smembers stu
(empty list or set)
redis 127.0.0.1:6379> select 1 #选择db 1
OK
redis 127.0.0.1:6379[1]> smembers stu
1) "zhangsan01"
2) "wangwu"
12)sort
语法:sort key [BY pattern] [LIMIT offset count] [GET pattern [GET pattern ...]] [ASC|DESC] [ALPHA] [STORE destination]
解释:返回或保持给定列表,集合,有序集合key中经过排序的元素
redis 127.0.0.1:6379> sort lst.tech limit 0 2 alpha desc #按字符集排序  
1) "tec06"
2) "tec05"
redis 127.0.0.1:6379> sort lst.stud
1) "1"
2) "2"
3) "3"
redis 127.0.0.1:6379> sort lst.stud desc
1) "3"
2) "2"
3) "1"
redis 127.0.0.1:6379> keys stu.*
1) "stu.name.2"
2) "stu.name.3"
3) "stu.level.1"
4) "stu.level.2"
5) "stu.level.3"
6) "stu.name.1"
redis 127.0.0.1:6379> sort lst.stud by stu.level.[i] desc get stu.level.[/i] get stu.name.*
1) "3"
2) "admin"
3) "2"
4) "joe"
5) "1"
6) "jim"
redis 127.0.0.1:6379> sort lst.stud by stu.level.[i] asc get stu.name.[/i]
1) "jim"
2) "joe"
3) "admin"
sort虽然很“厉害”,但尽量不要让redis服务器来sort大量的数据。可以通过设定阀值减少要sort的数据,或把排序操作向前移,在web服务器或各个应用上来sort。

3 个评论

要是讲一下redis的应用场景会更好!
你觉得redis应用场景最多是什么 我们线上是缓存数据,比如监控类的一些开关状态,或者监控频率,然后定期来取,做相应监控操作。
初学者。对应用场景没什么概念。。。

要回复文章请先登录注册