redis基本数据结构操作：

0.基本的常用key操作和数据库操作：

keys *查看当前库所有key (匹配：keys *1)

127.0.0.1:6379> set username qiuge OK 127.0.0.1:6379> set age 18 OK 127.0.0.1:6379> keys * 1) "age" 2) "username"

exists key判断某个key是否存在

127.0.0.1:6379> keys * 1) "age" 2) "username" 127.0.0.1:6379> exists username (integer) 1 127.0.0.1:6379> exists gender (integer) 0

type key 查看你的key是什么类型

127.0.0.1:6379> type username string 127.0.0.1:6379> type age string

del key 删除指定的key数据

127.0.0.1:6379> keys * 1) "age" 2) "username" 127.0.0.1:6379> del username (integer) 1 127.0.0.1:6379> keys * 1) "age"

unlink key 根据value选择非阻塞删除：仅将keys从keyspace元数据中删除    
    
    
，真正的删除会在后续异步操作    
    
    
。

127.0.0.1:6379> keys * 1) "age" 127.0.0.1:6379> unlink age (integer) 1 127.0.0.1:6379> keys * (empty array)

expire key 10 10秒钟：为给定的key设置过期时间

ttl key 查看还有多少秒过期     


     


     


   ，-1表示永不过期




 




 




 

，-2表示已过期

127.0.0.1:6379> keys * (empty array) 127.0.0.1:6379> set username qiuge OK 127.0.0.1:6379> ttl username (integer) -1 127.0.0.1:6379> expire username 10 (integer) 1 127.0.0.1:6379> ttl username (integer) 6 127.0.0.1:6379> ttl username (integer) 1 127.0.0.1:6379> ttl username (integer) -2 127.0.0.1:6379> keys * (empty array) 127.0.0.1:6379> set username qiuge OK 127.0.0.1:6379> keys * 1) "username" 127.0.0.1:6379> expire username -1 (integer) 1 127.0.0.1:6379> ttl username (integer) -2 127.0.0.1:6379> keys * (empty array)

注意：如果设置为后台启动
   

   

   

，数据结构创建的时候默认是永久的     

     

     

  ，也就是说只要设置了 




  




  




  
，哪怕中途重启了服务器也还是存在的

  


  


  


，使用expire设置时间是秒数     
     
     
 ，设置时间为-1并不是设置为永久  




   




   




   ，而是一设置时间过期     


     


     


   。

select命令切换数据库

127.0.0.1:6379> flushall OK 127.0.0.1:6379> keys * (empty array) 127.0.0.1:6379> select 0 OK 127.0.0.1:6379> keys * (empty array) 127.0.0.1:6379> set username qiuge OK 127.0.0.1:6379> keys * 1) "username" 127.0.0.1:6379> select 5 OK 127.0.0.1:6379[5]> keys * (empty array) 127.0.0.1:6379[5]> set age 19 OK 127.0.0.1:6379[5]> keys * 1) "age"

dbsize查看当前数据库的key的数量

127.0.0.1:6379> keys * (empty array) 127.0.0.1:6379> dbsize (integer) 0 127.0.0.1:6379> set username qiuge OK 127.0.0.1:6379> set age 18 OK 127.0.0.1:6379> keys * 1) "username" 2) "age" 127.0.0.1:6379> dbsize (integer) 2

flushdb清空当前库

127.0.0.1:6379> select 0 OK 127.0.0.1:6379> keys * (empty array) 127.0.0.1:6379> set username qiuge OK 127.0.0.1:6379> keys * 1) "username" 127.0.0.1:6379> select 5 OK 127.0.0.1:6379[5]> keys * (empty array) 127.0.0.1:6379[5]> set age 19 OK 127.0.0.1:6379[5]> keys * 1) "age" 127.0.0.1:6379[5]> flushdb OK 127.0.0.1:6379[5]> keys * (empty array) 127.0.0.1:6379[5]> select 0 OK 127.0.0.1:6379> keys * 1) "username"

flushall通杀全部库

127.0.0.1:6379> select 0 OK 127.0.0.1:6379> keys * 1) "username" 127.0.0.1:6379> select 5 OK 127.0.0.1:6379[5]> keys * (empty array) 127.0.0.1:6379[5]> set username wangge OK 127.0.0.1:6379[5]> keys * 1) "username" 127.0.0.1:6379[5]> flushall OK 127.0.0.1:6379[5]> keys * (empty array) 127.0.0.1:6379[5]> select 0 OK 127.0.0.1:6379> keys * (empty array)