1、键值通用操作

• keys pattern:查找当前数据库中所有匹配pattern的键

  • pattern支持*,?,[]匹配
    • *:匹配任意（所有）选项
    • ？：任意一位
    • []：匹配其中包含的任意一项

  127.0.0.1:6379> keys *
  1) "key1"
  2) "mykey"
  3) "zs"
  4) "a"
  5) "w"
  6) "k"
  7) "ss"
  
  127.0.0.1:6379> keys ?
  1) "a"
  2) "w"
  3) "k"
  
  127.0.0.1:6379> keys [wak]
  1) "a"
  2) "w"
  3) "k"
  

• randomkey:抽取随机键

  127.0.0.1:6379> randomkey
  "key1"
  127.0.0.1:6379> randomkey
  "k"
  127.0.0.1:6379> randomkey
  "zs"
  

• exists key：判断是否存在键key，返回1 或 0

  127.0.0.1:6379> exists k
  (integer) 1
  127.0.0.1:6379> exists pp
  (integer) 0
  

• type key：判断键的类型

  127.0.0.1:6379> type k
  list
  

• del key

  127.0.0.1:6379> keys *
  1) "key1"
  2) "mykey"
  3) "zs"
  4) "a"
  5) "w"
  6) "k"
  7) "ss"
  
  127.0.0.1:6379> del ss
  (integer) 1
  
  127.0.0.1:6379> keys *
  1) "key1"
  2) "mykey"
  3) "zs"
  4) "a"
  5) "w"
  6) "k"
  

• rename key newname

  # 正常情况下
  127.0.0.1:6379> keys *
  1) "key1"
  2) "mykey"
  3) "zs"
  4) "a"
  5) "w"     <---
  6) "k"
  
  127.0.0.1:6379> rename w wa
  OK
  
  127.0.0.1:6379> keys *
  1) "key1"
  2) "wa"    <----
  3) "mykey"
  4) "zs"
  5) "a"
  6) "k"
  

  # 如果重命名与已有键名重回
  127.0.0.1:6379> keys *
  1) "key1"
  2) "mykey"
  3) "a"   < -- hash
  4) "zs"
  5) "k"
  127.0.0.1:6379> type a
  hash
  127.0.0.1:6379> set aa "new"            <-- string
  OK
  127.0.0.1:6379> rename a aa
  OK
  127.0.0.1:6379> keys *
  1) "key1"
  2) "mykey"
  3) "aa"                  <-- hash
  4) "zs"
  5) "k"
  127.0.0.1:6379> type aa
  hash
  

  • 重命名（new）与已有键（old）名重合，会覆盖重合的键（old），相当于将键（old）的类型改写为重命名键（new）的类型

• renamenx key

  • 与rename一样，但当newkey存在时，不进行操作

  127.0.0.1:6379> keys *
  1) "key1"
  2) "mykey"
  3) "aa"
  4) "zs"
  5) "k"
  
  127.0.0.1:6379> renamenx a aa
  (integer) 0
  127.0.0.1:6379> keys *
  1) "key1"
  2) "mykey"
  3) "a"      <--没有改变
  4) "aa"
  5) "zs"
  6) "k"
  

• select 数据库编号（默认使用0号数据库）

• flushdb:清空数据

• move key 数据库编号

  #默认0号数据库
  127.0.0.1:6379> set q 123
  OK
  127.0.0.1:6379> move q 1
  (integer) 1
  127.0.0.1:6379> keys *
  1) "key1"
  2) "mykey"
  3) "a"
  4) "aa"
  5) "zs"
  6) "k"          #没有q
  
  127.0.0.1:6379> select 1
  OK
  127.0.0.1:6379[1]> keys *
  (empty list or set)
  127.0.0.1:6379[1]> keys *
  1) "q"
  

• ttl key:查询有效期

127.0.0.1:6379> ttl a
(integer) -1        -->永久有效
127.0.0.1:6379> ttl q
(integer) -2        -->不存在

• expire key seconds：设置生命周期

  127.0.0.1:6379> expire o 123
  (integer) 1
  127.0.0.1:6379> ttl o
  (integer) 119
  

• pexpire key ms:设置有效期，单位为毫秒
• persist key：设置永久有效

  127.0.0.1:6379> ttl o
  (integer) 33
  127.0.0.1:6379> persist o
  (integer) 1
  127.0.0.1:6379> ttl o
  (integer) -1