【Redis】四数据类型 String

偏执的太偏执、 2022-08-21 14:55 216阅读 0赞

# 【Redis】四 数据类型 String #

# 一个键最多存储 512 MB #

## get / set ##

set key value [ex seconds / px milliseconds / nx /xx ]同名key覆盖 
    
    
    
    
    127.0.0.1:6379> set test 'this is a test'
    OK
    127.0.0.1:6379> get test
    "this is a test"
    127.0.0.1:6379> set test 'this is a aaaaaa'
    OK
    127.0.0.1:6379> get test
    "this is a aaaaaa"
    127.0.0.1:6379> 
    
    
    ##无key返回nil
    127.0.0.1:6379> get notkey
    (nil)
    127.0.0.1:6379>

## getset ##

127.0.0.1:6379> set test 'test'
    OK
    127.0.0.1:6379> get test
    "test"
    127.0.0.1:6379> getset test 'cccc'
    "test"
    127.0.0.1:6379> getset notkey  'notkey'
    (nil)

## gettrange key start end 截取 ##

127.0.0.1:6379> getrange test 0 3
    "this"
    127.0.0.1:6379> get test
    "this is a test"
    127.0.0.1:6379> getrange test 0 -1
    "this is a test"
    127.0.0.1:6379> getrange test 0 -2
    "this is a tes"
    127.0.0.1:6379> getrange test 0 -3
    "this is a te"
    127.0.0.1:6379> getrange test -4 -1
    "test"

## setrange key offset value 设置偏移量 ##

127.0.0.1:6379> set test 'hello test'
    OK
    127.0.0.1:6379> get test
    "hello test"
    127.0.0.1:6379> setrange test 6 'world'
    (integer) 11
    127.0.0.1:6379> get test
    "hello world"
    127.0.0.1:6379> strlen test
    (integer) 11
    
    //如Key原字符长度小于偏移量 , 会以\x00填充
    127.0.0.1:6379> exists notkey48349
    (integer) 0
    127.0.0.1:6379> setrange notkey48349 5 'world'
    (integer) 10
    127.0.0.1:6379> get notkey48349
    "\x00\x00\x00\x00\x00world"

## mset/mget key value \[key value … \] 批量设置/ 读取 ##

127.0.0.1:6379> mset t1 1 t2 2
    OK
    
    127.0.0.1:6379> mget t1  t2 
    1) "1"
    2) "2"
    
    127.0.0.1:6379> mget t1  t2 t3 t4
    1) "1"
    2) "2"
    3) (nil)
    4) (nil)

## strlen key 长度 ##

127.0.0.1:6379> get test
    "cccc"
    127.0.0.1:6379> strlen test
    (integer) 4
    
    127.0.0.1:6379> strlen notkey321
    (integer) 0

## exists 判断key是否存在 ##

127.0.0.1:6379> get test
    "hello world"
    127.0.0.1:6379> exists test
    (integer) 1
    127.0.0.1:6379> exists notkey48349
    (integer) 0
    127.0.0.1:6379>

## setnx 当Key不存在,才成功 ##

127.0.0.1:6379> 
    127.0.0.1:6379> exists notkey98345
    (integer) 0
    127.0.0.1:6379> setnx notkey98345 'notkey98345'
    (integer) 1
    127.0.0.1:6379> setnx notkey98345 'notkey98345'
    (integer) 0
    127.0.0.1:6379> get notkey98345
    "notkey98345"

## setex key 多少秒时间过期 ##

原子操作 set key / expire key seconds

当 key 不存在时，返回 -2 。 当 key 存在但没有设置剩余生存时间时，返回 -1 。 否则，以毫秒为单位，返回 key 的剩余生存时间。
    注意：在 Redis 2.8 以前，当 key 不存在，或者 key 没有设置剩余生存时间时，命令都返回 -1 。
    127.0.0.1:6379> setex test 60 'test'
    OK
    127.0.0.1:6379> get test
    "test"
    127.0.0.1:6379> ttl test
    (integer) 43
    127.0.0.1:6379> ttl test
    (integer) 40
    127.0.0.1:6379> ttl test
    (integer) 14
    127.0.0.1:6379> ttl test
    (integer) -2
    127.0.0.1:6379> ttl test
    (integer) -2
    127.0.0.1:6379> ttl test
    (integer) -2
    127.0.0.1:6379> get test
    (nil)

## setex key 原子操作 相当于 set key / expire key seconds ##

127.0.0.1:6379> set test 'test'
    OK
    127.0.0.1:6379> expire test 10
    (integer) 1
    127.0.0.1:6379> ttl test
    (integer) 6
    127.0.0.1:6379> ttl test
    (integer) 4
    127.0.0.1:6379> ttl test
    (integer) 3
    127.0.0.1:6379> ttl test
    (integer) 2
    127.0.0.1:6379> ttl test
    (integer) 2
    127.0.0.1:6379> ttl test
    (integer) -2
    127.0.0.1:6379> ttl test
    (integer) -2
    127.0.0.1:6379> get tst
    (nil)
    127.0.0.1:6379> get test
    (nil)

## msetnx key不存在成功 原子性 ##

127.0.0.1:6379> msetnx t5 't5' t6 't6'
    (integer) 1
    127.0.0.1:6379> get t5
    "t5"
    127.0.0.1:6379> get t6
    "t6"
    127.0.0.1:6379> msetnx t5 't5' t6 't6'
    (integer) 0
    127.0.0.1:6379> msetnx t5 't5' t6 't6' t7 't7'
    (integer) 0
    127.0.0.1:6379> exists t7
    (integer) 0

## psetex 毫秒 key 生命周期 ##

127.0.0.1:6379> psetex hello 20000 'hello world'
    OK
    127.0.0.1:6379> pttl hello
    (integer) 17672
    127.0.0.1:6379> ttl hello
    (integer) 12
    127.0.0.1:6379> exists hello
    (integer) 0

## 参数 ##

<table> 
 <thead> 
  <tr> 
   <th>command</th> 
   <th align="left">explain</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>ex seconds</td> 
   <td align="left">过期时间 set key value ex seconds 等同 setex</td> 
  </tr> 
  <tr> 
   <td>px milliseconds</td> 
   <td align="left">毫秒过期时间 set key value px milliseconds 等同 psetex</td> 
  </tr> 
  <tr> 
   <td>nx</td> 
   <td align="left">key不存在 才设置成功 set key value nx 等同 setnx</td> 
  </tr> 
  <tr> 
   <td>xx</td> 
   <td align="left">key已经存在才成功</td> 
  </tr> 
 </tbody> 
</table>

127.0.0.1:6379> set t93 'hello world' ex 100 nx 
    OK
    127.0.0.1:6379> get t93
    "hello world"
    127.0.0.1:6379> ttl t93
    (integer) 85

## ex px 后者覆盖前者 ##

127.0.0.1:6379> set t94 't94' ex 100 px 30000
    OK
    127.0.0.1:6379> ttl t94
    (integer) 25
    127.0.0.1:6379> ttl t94
    (integer) 22
    127.0.0.1:6379> ttl t94
    (integer) 19
    127.0.0.1:6379> ttl t94
    (integer) 14
    127.0.0.1:6379> pttl t94
    (integer) 8532
    127.0.0.1:6379> pttl t94
    (integer) 5710
    127.0.0.1:6379> pttl t94
    (integer) 4286
    127.0.0.1:6379> pttl t94
    (integer) 1078
    127.0.0.1:6379> pttl t94
    (integer) -2
    127.0.0.1:6379> pttl t94
    (integer) -2
    127.0.0.1:6379> ttl t94
    (integer) -2

## incr 自增 ##

127.0.0.1:6379> set count 1
    OK
    127.0.0.1:6379> get count
    "1"
    127.0.0.1:6379> incr count
    (integer) 2
    127.0.0.1:6379> incr count
    (integer) 3
    
    // 当key不纯在
    127.0.0.1:6379> exists number 
    (integer) 0
    127.0.0.1:6379> incr number
    (integer) 1
    127.0.0.1:6379> get number
    "1"
    
    //原key值不是数值
    127.0.0.1:6379> set test 'txt'
    OK
    127.0.0.1:6379> incr test
    (error) ERR value is not an integer or out of range
    127.0.0.1:6379>

## incrby 指定增加量 ##

127.0.0.1:6379> set test 0
    OK
    127.0.0.1:6379> incrby test 5
    (integer) 5
    127.0.0.1:6379> get test
    "5"
    127.0.0.1:6379> incrby test -5
    (integer) 0
    127.0.0.1:6379> get test
    "0"
    
    //浮点数异常
    127.0.0.1:6379> incrby test 1.1
    (error) ERR value is not an integer or out of range

## incrbyfloat 可以设置整数 ##

127.0.0.1:6379> incrbyfloat  test 1.1
    "1.1"
    127.0.0.1:6379> incrbyfloat  test 1.1
    "2.2"
    127.0.0.1:6379> incrbyfloat  test 1.1
    "3.3"
    127.0.0.1:6379> incrbyfloat  test 1.1
    "4.4"
    127.0.0.1:6379> get test
    "4.4"
    //整数
    127.0.0.1:6379> incrbyfloat test 7
    "11.4"

## decr ##

127.0.0.1:6379> set test 7
    OK
    127.0.0.1:6379> decr test
    (integer) 6

## decrby ##

127.0.0.1:6379> set test 19
    OK
    127.0.0.1:6379> decr test
    (integer) 18
    127.0.0.1:6379> decrby  test 3
    (integer) 15
    127.0.0.1:6379> decrby  test 3.3
    (error) ERR value is not an integer or out of range

## 无decrbyfloat ##

## append ##

127.0.0.1:6379> set test '1'
    OK
    127.0.0.1:6379> append test '23'
    (integer) 3
    127.0.0.1:6379> get test
    "123"
    
    
    
    127.0.0.1:6379> exists notkey89983
    (integer) 0
    127.0.0.1:6379> append notkey89983 '_'
    (integer) 1
    127.0.0.1:6379> get notkey89983
    "_"

--------------------

# Hash #

# List #

127.0.0.1:6379> lpush t1 a b c 
    (integer) 3
    127.0.0.1:6379> 
    
    
    ## key不是string会error
    127.0.0.1:6379> get t1
    (error) WRONGTYPE Operation against a key holding the wrong kind of value
    127.0.0.1:6379>

# Set #

# Zset #