---
layout: post
title: redis 2：redis 一般命令操作
category: 技术
tags:  Redis
keywords: 
description: 
---

{:toc}


## Redis一般命令

redis是键值对的内存数据库，属于Nosql范畴
登录redis自带的客户端

```bash
#redis-cli
127.0.0.1:6379>
```


### 1.设置redis 键值对

```redis
> set foo bar  #设置键foo的值为"bar"
OK #设置成功
```

### 2.获得redis 键值对

```redis
> get foo #根据键获得值
"bar" #返回的结果
```

### 3.删除键值对 

```redis
127.0.0.1:6379> del foo foo2 foo3 #删除键值对，可删除多个
(integer) 3 #删除成功的键值对的个数
```

### 4.返回空

```redis
127.0.0.1:6379> get foo #如果键值对不存在，返回nil
(nil)
```


### 5.判断键值对是否存在，返回0：不存在，返回1：存在；只能查询一个键。

```redis
127.0.0.1:6379> EXISTS foo
(integer) 0
127.0.0.1:6379> set foo bar
OK
127.0.0.1:6379> EXISTS foo
(integer) 1
127.0.0.1:6379> EXISTS foo foo2 foo3
(error) ERR wrong number of arguments for 'exists' command
```

### 6.设置键值对有效期

```redis
#设置foo键有效期为32秒
127.0.0.1:6379> EXPIRE foo 32 
(integer) 1
```

### 7.根据键的表达式，查找符合表达式的键

```redis
127.0.0.1:6379> keys foo*
1) "foo3"
2) "foo2"
3) "foo"
```


### 8.自动将一个key从一个redis实例传输到另一个	

	MIGRATE host port key destination-db timeout  
	
	summary: Atomically transfer a key from a Redis instance to another one.
	
	since: 2.6.0


### 9.将一个key移到另一个数据库

	MOVE key db
	
	summary: Move a key to another database
	
	since: 1.0.0


### 10.检查内部的redis对象

	OBJECT subcommand [arguments [arguments ...]]  
	
	summary: Inspect the internals of Redis objects
	
	since: 2.2.3


### 11.从key中移除过期时间

	PERSIST key  
	
	summary: Remove the expiration from a key
	
	since: 2.2.0

```redis
127.0.0.1:6379> set foo bar
OK
127.0.0.1:6379> EXPIRE foo 32
(integer) 1
127.0.0.1:6379> PERSIST foo
(integer) 1
```

### 12.获取键值对的存活时间(微秒)

	PTTL key
	
	summary: Get the time to live for a key in milliseconds
	
	since: 2.6.0


```redis
127.0.0.1:6379> EXPIRE foo 32
(integer) 1
127.0.0.1:6379> pttl foo
(integer) 27944
```

### 13.获取键值对存活时间(秒)

	TTL key
	
	summary: Get the time to live for a key
	
	since: 1.0.0


### 14.设置微秒级别的unix形式的时间，键值对存活时间

	PEXPIREAT key milliseconds-timestamp
	
	summary: Set the expiration for a key as a UNIX timestamp specified in milliseconds
	
	since: 2.6.0


### 15.随机获取一个键

	RANDOMKEY -
	
	summary: Return a random key from the keyspace
	
	since: 1.0.0


```redis
127.0.0.1:6379> RANDOMKEY
"foo2"
```

### 16.重命名键

	RENAME key newkey
	
	summary: Rename a key
	
	since: 1.0.0


```redis
127.0.0.1:6379> rename foo12 foo13
OK
```

### 17.重命名键，新键不存在时

	RENAMENX key newkey
	
	summary: Rename a key, only if the new key does not exist
	
	since: 1.0.0


```redis
127.0.0.1:6379> RENAMENX foo13 foo3 #foo3已经存在执行不成功
(integer) 0
```

### 18.备份键值对

	DUMP key
	
	summary: Return a serialized version of the value stored at the specified key.
	
	since: 2.6.0

```redis
127.0.0.1:6379> dump foo
"\x00\x03bar\x06\x00pS!\xe0\x1b3\xc1\x84"
```

### 19.还原键值对

	RESTORE key ttl serialized-value
	
	summary: Create a key using the provided serialized value, previously obtained using DUMP.
	
	since: 2.6.0


### 20.获取键的类型

	TYPE key
	
	summary: Determine the type stored at key
	
	since: 1.0.0


```redis
127.0.0.1:6379> type foo3
string
```

### 21.按键排序

	SORT key [BY pattern] [LIMIT offset count] [GET pattern [GET pattern ...]] [ASC|DESC] [ALPHA] [STORE destination]
	
	summary: Sort the elements in a list, set or sorted set
	
	since: 1.0.0



### 22.设置微秒级别的键值对存活时间

	PEXPIRE key milliseconds
	
	summary: Set a key's time to live in milliseconds
	
	since: 2.6.0
	
### 23.清空redis

```
>flushdb
```

## Redis的String类型的命令操作 

### 1.将值添加到键的值得后面

	APPEND key value
	
	summary: Append a value to a key
	
	since: 2.0.0

```redis
127.0.0.1:6379> append foo3 barbar
(integer) 10
127.0.0.1:6379> get foo3
"bar3barbar"
```

### 2.

	BITCOUNT key [start] [end]
	
	summary: Count set bits in a string
	
	since: 2.6.0

```redis
127.0.0.1:6379> bitcount foo3
(integer) 34
127.0.0.1:6379> bitcount foo13
(integer) 16
```

### 3."不懂"

	BITOP operation destkey key [key ...]
	
	summary: Perform bitwise operations between strings
	
	since: 2.6.0


### 4.将值减小1(键对应的值必须为int)

	DECR key
	
	summary: Decrement the integer value of a key by one
	
	since: 1.0.0


```redis
127.0.0.1:6379> set num1 13
OK
127.0.0.1:6379> get num1
"13"
127.0.0.1:6379> decr num1
(integer) 12
127.0.0.1:6379> get num1
"12"
```

### 5.将值减小指定大小(键对应的值必须为int)

	DECRBY key decrement
	
	summary: Decrement the integer value of a key by the given number
	
	since: 1.0.0

```redis
127.0.0.1:6379> get num1
"12"
127.0.0.1:6379> DECRBY num1 6
(integer) 6
127.0.0.1:6379> get num1
"6"
```

### 6.为键重新复制，并返回之前的旧值

	GETSET key value
	
	summary: Set the string value of a key and return its old value
	
	since: 1.0.0


### 7. 

	GETBIT key offset
	
	summary: Returns the bit value at offset in the string value stored at key
	
	since: 2.2.0


### 8.

	GETRANGE key start end
	
	summary: Get a substring of the string stored at a key
	
	since: 2.4.0


### 9.为key设置string值，并返回原先的值

	GETSET key value
	
	summary: Set the string value of a key and return its old value
	
	since: 1.0.0


```redis
127.0.0.1:6379> get foo13
"bar12nametest"
127.0.0.1:6379> getset foo13 test
"bar12nametest"
```

### 10. 将value类型为int的值加1


	INCR key
	
	summary: Increment the integer value of a key by one
	
	since: 1.0.0

```redis
127.0.0.1:6379> set num 10
OK
127.0.0.1:6379> get num
"10"
127.0.0.1:6379> INCR num
(integer) 11
```

### 11. 将value类型为int的值加指定的数

	INCRBY key increment
	
	summary: Increment the integer value of a key by the given amount
	
	since: 1.0.0

```redis
127.0.0.1:6379> get num
"11"
127.0.0.1:6379> INCRBY num 10
(integer) 21
127.0.0.1:6379> get num
"21"
```

### 12.将value类型为float的值加上指定的数

	INCRBYFLOAT key increment
	
	summary: Increment the float value of a key by the given amount
	
	since: 2.6.0


```redis
127.0.0.1:6379> set flo 11.2
OK
127.0.0.1:6379> get flo
"11.2"
127.0.0.1:6379> INCRBYFLOAT flo 12.0
"23.2"
```

### 13.获取多个key的value

	MGET key [key ...]
	
	summary: Get the values of all the given keys
	
	since: 1.0.0

```redis
127.0.0.1:6379> MGET foo2 foo3 foo4
1) "bar2"
2) "bar3barbar"
3) (nil)
```


### 14.设置多个key的value

	MSET key value [key value ...]
	
	summary: Set multiple keys to multiple values
	
	since: 1.0.1

```redis
127.0.0.1:6379> MSET foo2 bar22 foo3 bar33 foo4 bar44
OK
127.0.0.1:6379> MGET foo2 foo3 foo4
1) "bar22"
2) "bar33"
3) "bar44"
```

### 15.当所有的key都不存在时，设置value

	MSETNX key value [key value ...]
	
	summary: Set multiple keys to multiple values, only if none of the keys exist
	
	since: 1.0.1

```redis
127.0.0.1:6379> MSETNX foo2 bar23 foo5 bar55 ##因为foo2键已经存在
(integer) 0
```

### 16.设置键的微秒生存时间和值

	PSETEX key milliseconds value
	
	summary: Set the value and expiration in milliseconds of a key
	
	since: 2.6.0


### 17.设置键的秒生存时间和值

	SETEX key seconds value
	
	summary: Set the value and expiration of a key
	
	since: 2.0.0



### 18.设置值

	SET key value [EX seconds] [PX milliseconds] [NX|XX]
	
	summary: Set the string value of a key
	
	since: 1.0.0


### 19.

	SETBIT key offset value
	
	summary: Sets or clears the bit at offset in the string value stored at key
	
	since: 2.2.0


### 20.在键不存在时，设置值

	SETNX key value
	
	summary: Set the value of a key, only if the key does not exist
	
	since: 1.0.0


### 21.从offset位置写入新的值内容

	SETRANGE key offset value
	
	summary: Overwrite part of a string at key starting at the specified offset
	
	since: 2.2.0

```redis
127.0.0.1:6379> set foo5 jing
OK
127.0.0.1:6379> get foo5
"jing"
127.0.0.1:6379> SETRANGE foo5 3 test
(integer) 7
127.0.0.1:6379> get foo5
"jintest"
```



### 22.获取值得长度

	STRLEN key
	
	summary: Get the length of the value stored in a key
	
	since: 2.2.0

```redis
127.0.0.1:6379> STRLEN foo5
(integer) 4
```