Redis入门

• 五大数据类型
• • String(字符串)
  • List

五大数据类型

1. Redis-key
2. String
3. List
4. Set
5. Hash
6. Zset

String(字符串)

String常用命令如下:

127.0.0.1:6379> exists name //查看某字段是否存在
(integer) 1
127.0.0.1:6379> keys * //查看该数据库下所有key
1) "name"
127.0.0.1:6379> get name //查看key对应的value
"wenzemin"
127.0.0.1:6379> expire name 10 //设置字段有效时间(s)
(integer) 1
127.0.0.1:6379> get name //10s之后查看,显示为null
(nil)
127.0.0.1:6379> keys *
(empty array)
127.0.0.1:6379> set name wenzemin //设置K-V键值对
OK
127.0.0.1:6379> set age 1 
OK
127.0.0.1:6379> type age 查看某字段的数据类型
string
127.0.0.1:6379> append name ",hello" //在某字段后面追加内容,若该字段不存在,则相当于set name xxx
(integer) 14
127.0.0.1:6379> get name
"wenzemin,hello"
127.0.0.1:6379> strlen name //获取某字段对应的value值的长度
(integer) 14

#########################################################

127.0.0.1:6379> set views 0 //设置初始浏览量为0
OK
127.0.0.1:6379> incr views  //自增1
(integer) 1
127.0.0.1:6379> incr views 
(integer) 2
127.0.0.1:6379> get views
"2"
127.0.0.1:6379> decr views //自减1
(integer) 1
127.0.0.1:6379> decr views
(integer) 0
127.0.0.1:6379> get views
"0"
127.0.0.1:6379> incrby views 10 //设置步长,指定增量为10
(integer) 10
127.0.0.1:6379> incrby views 10
(integer) 20
127.0.0.1:6379> decrby views 5 
(integer) 15
127.0.0.1:6379> decrby views 5
(integer) 10

########################################################

//设置字符串范围(Range)
127.0.0.1:6379> set key hello,world
OK
127.0.0.1:6379> get key
"hello,world"
127.0.0.1:6379> getrange key 0 4  //截取字符串[0,4]
"hello"
127.0.0.1:6379> getrange key 0 -14 
"h"
127.0.0.1:6379> getrange key 0 -1 //获取全部字符串,和get一样
"hello,world"

//替换
127.0.0.1:6379> setrange key 6 sunshine //从某下标开始替换
(integer) 14
127.0.0.1:6379> get key
"hello,sunshine"

//setex(set with expire) 设置过期时间
//setnx(set if not exist)不存在再设置(在分布式锁中常常使用)
127.0.0.1:6379> setex name 10 maria 设置name过期时间为10s
OK
127.0.0.1:6379> ttl name //查看有效时间
(integer) 6
127.0.0.1:6379> setnx hobby study
(integer) 1
127.0.0.1:6379> keys *
1) "hobby"
2) "key"
127.0.0.1:6379> get name
(nil)
127.0.0.1:6379> ttl name
(integer) -2
127.0.0.1:6379> setnx hobby running //hobby如果存在,则创建失败
(integer) 0
127.0.0.1:6379> get hobby
"study"

###########################################################

mset
mget
127.0.0.1:6379> mset k1 v1 k2 v2 k3 v3 //同时设置多个值
OK
127.0.0.1:6379> keys *
1) "k2"
2) "k1"
3) "k3"
127.0.0.1:6379> mget k1 k2 k3 //同时获取多个值
1) "v1"
2) "v2"
3) "v3"
127.0.0.1:6379> msetnx k1 v1 k4 v4 //msetnx是一个原子性操作,要么全部成功,要么全部失败
(integer) 0
127.0.0.1:6379> get k4
(nil)

#######################################################
//对象 
set user:1 {name:zhangsan,age:18}
设置一个user:1对象,值为json字符串来保存一个对象
127.0.0.1:6379> mset user:1:name zhangsan user:1:age 18
OK
127.0.0.1:6379> mget user:1:name user:1:age
1) "zhangsan"
2) "18"

127.0.0.1:6379> getset db redis //先get然后set
(nil)
127.0.0.1:6379> get db
"redis"
127.0.0.1:6379> getset db mongodb
"redis"
127.0.0.1:6379> get db
"mongodb"

List

在Redis里面,可以用LIst实现栈、队列、阻塞队列
所有的List命令都是用 l 开头

127.0.0.1:6379> LPUSH list one //将一个值或多个值插入到列表头部(左)
(integer) 1
127.0.0.1:6379> LPUSH list two
(integer) 2
127.0.0.1:6379> LPUSH list three
(integer) 3
127.0.0.1:6379> LRANGE list 0 -1
1) "three"
2) "two"
3) "one"
127.0.0.1:6379> LRANGE list 0 1
1) "three"
2) "two"
127.0.0.1:6379> RPUSH list zero  //将一个值或多个值插入到列表尾部(右)
(integer) 4
127.0.0.1:6379> LRANGE list 0 -1
1) "three"
2) "two"
3) "one"
4) "zero"
![在这里插入图片描述](https://www.www.zyiz.net/i/ll/?i=20210606181646477.png?,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl81NjYxNjMyNQ==,size_16,color_FFFFFF,t_70#pic_center)
127.0.0.1:6379> LPOP list  //移除list的第一个元素
"three"
127.0.0.1:6379> RPOP list //移除list的最后一个元素
"zero"
127.0.0.1:6379> LRANGE list 0 -1
1) "two"
2) "one"
127.0.0.1:6379> LINDEX list 0  //通过下标获得list中的某一个值
"two"
127.0.0.1:6379> LINDEX list 1
"one"
127.0.0.1:6379> LLEN list  //返回列表的长度Llen,命令不区分大小写
(integer) 2