Table of contents
2. redis installation (ubuntu)
2. list (list) type use command
3. set (collection) type command
4. SortedSet (ordered set type) command
1. Concept
A NoSQL non-relational database is a database that does not use a relational model to organize data. It is usually used to store unstructured or semi-structured data. It does not support or only partially supports the SQL language to meet eventual consistency. There are many types of non-relational databases, such as key-value databases, document databases, columnar databases, graph databases, time series databases , etc. The advantages of non-relational databases are high flexibility, high performance, and strong scalability , and are suitable for processing massive data and complex data types. The disadvantage of non-relational databases is that they do not provide transaction support, cannot guarantee data integrity and security , and their functions are not as perfect as relational databases.
Redis is a non-relational database, which is a kind of key-value database . It uses key-value pairs to store data and supports multiple types of values, such as strings, hashes, lists, sets, ordered sets, etc. The characteristics of Redis are:
High performance : Redis is a memory-based database with a very fast read and write speed, which can reach 100,000 reads and writes per second.
Persistence : Redis supports two persistence methods, one is snapshot (snapshotting), which saves the data in memory to the disk at regular intervals; Write operations are logged to a file.
Distributed : Redis supports master-slave replication (master-slave replication), which can realize data backup and load balancing
Rich functions : In addition to providing basic addition, deletion, modification and query operations, Redis also provides transactions, publish and subscribe, Lua scripts, pipelines, etc. Advanced Features.
Easy to use : Redis is written in C language, the code is concise, and it is very convenient to install and use.
2. redis installation (ubuntu)
1. Download tools and install
Chinese website: http://redis.cn
Official website: http://redis.io
Upload the downloaded package to the linux server, use the command to decompress and install as shown in the figure below
The command is as follows
解压命令
tar zxvf redis-4.0.8.tar.gz
进入到解压后目录，执行下面命令
make
sudo make installUse the command to test whether the installation is successful
启动redis
redis-server
打开一个新终端，使用客户端连接
redis-cli #默认连接本地主机，绑定6379端口
redis-cli -p 端口号 #指定端口连接本地
redis-cli -h IP地址 -p 端口号 #连接远程主机
通过客户端关闭服务器
shutdown
客户端的测试命令
pingAs shown below
2. Redis uses commands
1. String type use command
字符串类型都是以
key->string
value->string
的形式
命令1
set key value #表示创建一个键值对，键值为key，值为value，如果已经存在则会被覆盖
命令2
keys * #表示查看所有的键值
命令3
get key #获取到指定键值的值
命令4
mset [key value] #表示一次创建多个键值对，例：get h1 world1 h2 world2
命令5
mget [key] #一次获取到多个指定键值的值
命令6
append key value #在指定键值后追加字符，如果指定键值不存在则会创建该键值
命令7
strlen key #查看指定键值的值的长度
命令8
decr key #只可以使用到数字字符，指定的键值减1
命令9
incr key #只可以使用到数字字符，指定的键值加1
命令10
decrby key 数字n #只可以使用到数字字符，指定的键值的值减n
命令11
incrby key 数字n #只可以使用到数字字符，指定的键值的值加nThe following is an example of operation
2. list (list) type use command
列表类型以
key->string
value->list
形式
命令1
lpush key [value] #创建一条数据，将一个或多个值插入到列表key的表头
rpush key [value] #创建一条数据，将一个或多个值插入到列表key的表尾
命令2
lrange key start stop #遍历列表
key：遍历的列表名称
start：遍历的起始位置
stop：遍历的结束位置
命令3
lpop key #删除列表为key的表头元素
rpop key #删除列表为key的表尾元素
命令4
lindex key index #通过下表获取对应的值
key：要获取的列表名称
index：下标值
命令5
llen key #查看指定列表的长度
命令6
lrem key count value #根据参数 count 的值，移除列表中与参数 value 相等的元素。
count 的值可以是以下几种 :
count > 0: 从表头开始向表尾搜索，移除与 value 相等的元素，数量为 count 。
count < 0: 从表尾开始向表头搜索，移除与 value 相等的元素，数量为 count 的绝对值
count = 0 :移除表中所有与 value 相等的值The following is an example of operation
3. set (collection) type command
set类型以
key->string
value->set类型(string,string...)
形式存储
命令1
sadd key [member] #创建一个名称为key的集合，member为插入的值，插入到头部，不会有重复数据
命令2
smembers key #遍历集合
命令3
sdiff key1 key2 #求两个集合的差集
命令4
sinter key1 key2 #求两个集合的交集
命令5
sunion key1 key2 #求两个集合的并集
命令6
sdiffstore key key1 key2 #求key1和key2的集合的差集，并且把差集存放到key集合中
命令7
sinterstore key key1 key2 #和命令6一样，该命令求交集
命令8
sunionstore key key1 key2 #和命令6一样，该命令求并集
命令9
spop key #随机删除集合key中的一个元素
命令10
srem key [member] #删除集合key中指定的元素member
The following is an example of operation
4. SortedSet (ordered set type) command
有序集以
key->string
value->sorted[score,member]
的形式存储
命令1
zadd key [score,member] #创建一个有序集，插入一个或多个值到有序集key中
命令2
zrange key start stop [withscores] #遍历有序集key，按升序输出
zrevrange key start stop [withscores] #遍历有序集key，按降序输出
start：遍历的开始位置
stop：遍历的结束位置
命令3
zcount key min max #计算有序集key中，score值在min到max之间的个数
命令4
zrank key member #返回有序集key中成员member的排名，按成员score值递增排序
zrevrank key member #返回有序集key中成员member的排名，按成员score值递减排序
命令5
zrem key [member] #移除一个或多个元素
命令6
zscore key member #返回有序集key中成员member的score值
5.hsa (hash) type command
hash类型以
key->string
value->hash[field:value,field:value]
的形式存储
命令1
hset key field value #创建一个名为key的哈希表，并插入键值对field：value
命令2
hget key field #取出哈希表key中键为field的值
命令3
hmset key [field value] #可以同时插入多个键值对
命令4
hmget key [field] #可以同时获取多个值
命令5
hdel key [field] #删除哈希表中键值为field的值
命令6
hgetall key #输出哈希表的键和值
命令7
hkeys key #输出键
命令8
hvals key #输出值The following is an example of operation
6.key operation
命令1
del [key] #删除名称为key的键值对
命令2
keys * ？ [] #匹配key值
*：匹配一串字符
？：匹配一个字符
[]：匹配指定字符
命令3
expire key seconds #设置名称为key的键值存活实际，seconds表示秒
命令4
ttl key #查看存活时间，-1表示没有设置存活时间，-2表示不存在
命令5
persist key #移除给定key的生成时间
命令6
type key #返回key对应的value类型3. redis configuration file
The file redis.conf is in the directory where the package was decompressed above. If my package is redis-4.0.8.tar.gz, you need to enter the directory of redis-4.0.8 to find it.
The content meaning of some configuration files
1. bind 127.0.0.1 #绑定的ip地址，只有绑定的ip地址才可以访问到，注释默认所有ip地址都可访问
2. protected-mode yes #包含模式，要远程连接需要关闭，yes表示开启，no表示关闭
3. port 6379 #使用的端口号，默认6378
4.timeout 0 #超时时间，0表示不启用，>0表示启用
5.daemonize no #守护进程，no表示不是守护进程，yes表示是守护进程
6.pidfile /var/run/redis-b379.pid #如果不是守护进程不生效，如果是会生成一个pid文件，可以修改目录，./ -> 表示在redis启动的目录下
7.loglevel notice #日志级别
8.logfile "" #日志文件，要是守护进程才生效，这样表示不输出，
配置好文件后使用一下命令启动以及连接
启动：redis-server redis.conf
连接：redis-cli -p 端口号4. Redis data persistence
| Way | generate file | storage method | advantage | shortcoming |
| rdb mode | Generate .rdb file, open by default | Will write the data in the memory to the disk file in binary form | The file is relatively small, the recovery time is short, and the efficiency is high | Synchronize data at the frequency set by the user, which is easy to lose data and has low data integrity |
| aof way | Generate .aof file | Will write the command to generate the data to the disk file | Data synchronization every 1 second, high data integrity | Large files, recovery time bed, low efficiency |
Some configuration file content is also in the redis.conf file
1.rdb的刷新频率，任何一个满足都会刷新
save 900 1
save 300 10
save 60 10000
2.dbfilename dump.rdb #rdb文件的名字
3.dir ./ #生成的持久化文件保存的目录，rdb和aof
4.appendonly no #是否要打开aof模式，yes表示是，no表示否
5.appendfilename "appendonly.aof" #设置aof文件的名字some problems
1. Can aof and rdb be opened at the same time
Can
2. Can aof and rdb be closed at the same time
Can
Close rdb mode: save ""
3. The two modes are turned on at the same time. If data recovery is performed, how to choose
Efficiency considerations: rdb mode
Data integrity considerations: aof mode