redis键

• 永远的帮助命令，help @类型
• help @string
• help @list
• help @hash
• help @hyperloglog

1. keys *
   查看当前库所有的key

127.0.0.1:6379> set k1 v1
OK
127.0.0.1:6379> set k2 v2
OK
127.0.0.1:6379> keys *
1) "k2"
2) "k1"

2. exists key
   判断某个key是否存在

127.0.0.1:6379> set k1 v1
OK
127.0.0.1:6379> set k2 v2
OK
127.0.0.1:6379> exists k1
(integer) 1
127.0.0.1:6379> exists k3
(integer) 0

3. type key
   查看你的key是什么类型

127.0.0.1:6379> type k1
string

4. del key
   删除指定的key数据

127.0.0.1:6379> keys *
1) "k2"
2) "k1"
127.0.0.1:6379> del k1
(integer) 1
127.0.0.1:6379> keys *
1) "k2"

5. unlink key
   非阻塞删除，仅仅将keys从keyspace元数据中删除，真正的删除会在后续异步中操作

127.0.0.1:6379> set k1 v1
OK
127.0.0.1:6379> set k2 v2
OK
127.0.0.1:6379> keys *
1) "k1"
2) "k2"
127.0.0.1:6379> unlink k1
(integer) 1
127.0.0.1:6379> keys *
1) "k2"

6. 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> ttl k1
(integer) -2
127.0.0.1:6379> ttl k2
(integer) -1

7. expire key 秒钟
   为给定的key设置过期时间

127.0.0.1:6379> set k1 v1
OK
127.0.0.1:6379> expire k1 5
(integer) 1
127.0.0.1:6379> ttl k1
(integer) 2
127.0.0.1:6379> ttl k1
(integer) 1
127.0.0.1:6379> ttl k1
(integer) -2

8. move key dbindex[0-15]
   将当前数据库的key移动到给定的数据库db当中

127.0.0.1:6379> set k1 v1
OK
127.0.0.1:6379> keys *
1) "k1"
2) "k2"
127.0.0.1:6379> move k1 3
(integer) 1
127.0.0.1:6379> keys *
1) "k2"
127.0.0.1:6379> select 3
OK
127.0.0.1:6379[3]> keys *
1) "k1"

9. select dbindex
   切换数据库[0-15]，默认为0

127.0.0.1:6379> select 3
OK
127.0.0.1:6379[3]>

10. dbsize
    查看当前数据库key的数量

127.0.0.1:6379[3]> dbsize 
(integer) 1
127.0.0.1:6379[3]> set k2 v2
OK
127.0.0.1:6379[3]> dbsize 
(integer) 2

11. flushdb
    清空当前库

127.0.0.1:6379[3]> flushdb
OK
127.0.0.1:6379[3]> keys *
(empty array)
127.0.0.1:6379[3]> select 0
OK
127.0.0.1:6379> keys *
1) "k2"

12. flushall
    通杀全部库

127.0.0.1:6379> select 3
OK
127.0.0.1:6379[3]> set k2 v2
OK
127.0.0.1:6379[3]> flushall
OK
127.0.0.1:6379[3]> keys *
(empty array)
127.0.0.1:6379[3]> select 0
OK
127.0.0.1:6379> keys *
(empty array)