Redis's 2022 most complete five basic data types related knowledge and shell commands (String, List, Set, Hash, Zset)

1. Introduction

Quoting a paragraph on the Redis official website, Redis is an open source (BSD licensed), in-memory data structure storage system, which can be used as a database, cache, and message middleware. It supports many types of data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs and geospatial ( geospatial) Index radius query. Redis has built-in replication (replication), LUA scripting (Lua scripting), LRU driver events (LRU eviction), transactions (transactions) and different levels of disk persistence (persistence), and through Redis Sentinel (Sentinel) and automatic partition (Cluster ) provides high availability (high availability)

2. Basic shell commands of RedisKey

1. View all keys

keys *

2. Assign a value to the specified key value

set key值 value值

For example

set name xg

3. Get the value of the key

get key值

For example

get name

4. Determine whether the current key exists

exists key值

For example

exists name

5. Remove the current key

move key值 1

For example

move name 1

6. Set the expiration time of the key, in seconds

expire key值 10

For example

expire age 10

7. View the remaining time of the current key

ttl key值

For example

ttl age

8. View the type of the current key

type key值

For example

type age

Three, String data type shell command

1. String operations

1.1 Append a string, if the current key does not exist, it is equivalent to setkey

append key值 "value值"

For example

append name zhangsan
或者
append name "zhangsan"

1.2 Get the length of the string

strlen key值

For example

strlen name

1.3 String scope

(1) Intercept the string from 0 to 3, closed interval [0, 3]

getrange key值 起始位置 终止位置

For example

getrange name 0 3

(2) Get the string

getrange key值 0 -1

For example

getrange name 0 -1

1.4 Replace the string starting at the specified position

setrange key值 2 字符串

For example

setrange name 2 wee

2. Data operation

2.1 Increment by one

incr key值

For example

incr age

2.2 Decrement by one

decr key值

For example

decr age

2.3 Set the step size and specify the increment

After use, the original value will be increased by 10

incrby key值 步长值

For example

incrby age 10

2.4 Set the expiration time

Set the key value to xxx, which will expire after 30 seconds

setex key值 时间值 "value值"

For example

setex name 30 "zhangsan"

2.5 Set only if it does not exist

If the key value does not exist, create the key, if it exists, the creation fails

setnx key值 "value值"

For example

setnx name "zhangsan"

2.6 Setting multiple values ​​at the same time

mset key值1 value值1 key值2 value值2 key值3 value值3

For example

mset k1 v1 k2 v2 k3 v3

2.7 Get multiple values ​​at the same time

mget key值1 key值2 key值3

For example

mget k1 k2 k3

2.8 When there are multiple assignments, set it only if it does not exist

msetnx is an atomic operation

msetnx key值1 value值1 key值2 value值2

For example

msetnx k1 v1 k2 v2

3. Object

3.1 Set a user:1 object value as a json string to save an object

set user:{
    
    id}:{
    
    filed}

For example

set user:1 {
    
    name:zhangsan, age:3}

3.2 getset method

If there is a value, get the original value and set the new value
If there is no value, return nil

getset key值 value值

For example

getset name zhangsan

4. Usage scenarios

Counter
Counting the number of multiple units
Followers
Object cache storage

4. List data type shell command

1 Introduction

In redis, lists can be made into stacks, queues, and blocking queues.
And all list commands start with l, case insensitive

2. List operation

2.1 Insert a value or multiple values ​​into the head of the list (left)

lpush 列表名 数据

For example

lpush list one

2.2 Insert a value or multiple values ​​at the end of the list (right)

rpush 列表名 数据

For example

rpush list two

2.3 Obtain specific values ​​through intervals

lrange 列表名 起始位置 结束位置

For example

lrange list 0 2

2.4 Get all the values ​​of the list

lrange 列表名 0 -1

For example

lrange list 0 -1

2.5 Remove the first element of the list

lpop 列表名

For example

lpop list

2.6 Remove the last element of a list

rpop 列表名

For example

rpop list

3. Subscript operation

3.1 Obtain a value in the list by subscript

lindex 列表名 下标名

For example

lindex list 1

3.2 Return the length of the list

llen 列表名

For example

llen list

3.3 Remove the specified number of values ​​in the list set (exact match)

lrem 列表名 个数 value值

For example

lrem list 1 one

3.4 Intercept the specified length by subscript. (the list is changed, and only the intercepted elements are truncated)

ltrim 列表名 起始位置 结束位置

For example

ltrim list 1 2

3.5 Remove the last element of the list and move it to a new list

rpoplpush 原列表名 新列表名

For example

rpoplpush list list2

3.6 Replace the value of the specified subscript in the list with another value (update operation)

Determine whether the table exists. If it does not exist, an error will be reported when updating. If it exists, update the value of the current subscript.

lset 列表名 下标名 value值

For example

lset list 0 name

4. Insert operation

Insert a specific value before or after a value in the list

linsert 列表名 before 已存在的值 即将插入的值

linsert 列表名 after 已存在的值 即将插入的值

For example

linsert list before one three

linsert list after one three

5. Pay attention

It is actually a linked list, before Node after, left, and right can insert values.
If the key value does not exist, create a new linked list.
If the key value exists, add content
. If all values ​​​​are removed, an empty linked list also means that it does not exist
on both sides. Inserting or changing values ​​has the highest efficiency, and intermediate elements are relatively less efficient.
Message queuing, message queue (lpush rpop)
stack (lpush lpop)

Five, Set collection

1. Set collection related operations

1.1 Add data to the set collection

sadd set集合名 数据

For example

sadd myset one

1.2 View all values ​​of the set collection

smembers set集合名

For example

smembers myset

1.3 Determine whether a value is in the set collection

sismember set集合名 数据

For example

sismember myset one

1.4 Get the number of content elements in the set collection

scard set集合名

For example

scard myset

1.5 Remove the specified element in the set collection

srem set集合名 数据

For example

srem myset one

2. Random operation

2.1 Randomly extract an element

srandmember set集合名

For example

srandmember myset

2.2 Randomly extract a specified number of elements

srandmember set集合名 个数 

For example

srandmember myset 2

2.3 Randomly delete some elements in the set collection

spop set集合名

For example

spop myset

3. Move a specified value to another set collection

smove 原set集合名 新set集合名 value值

For example

smove myset myset2 one

4. Collection operations

4.1 Difference (SDIFF)

sdiff set集合1 set集合2

For example

sdiff set1 set2

4.2 Intersection

sinter set集合名1 set集合名2

For example

sinter set1 set2

4.3 Union

sunion set集合名1 set集合名2

For example

sunion set1 set2

6. Hash type data

1 Introduction

Its data type is a map collection, and key-map (the value is a map collection) is not much different from the String type in essence, it is still a simple key-value

2. Hash basic operation

2.1 set a specific key-value

hset hash名称 key值 value值

For example

hset myhash field1 zhangsan

2.2 Get a field value

hget hash名称 key值

For example

hget myhash field1

2.3 set multiple key-value values

hmset hash名称 key值1 value值1 key值2 value值2

For example

hmset myhash x1 y1 x2 y2

2.4 Get multiple field values

hmget hash名称 key值1 key值2

For example

hmget myhash x1 x2

2.5 Get all the data

hgetall hash名称

For example

hgetall myhash

2.6 Delete the key value specified by hash

hdel hash名称 key值

For example

hdel myhash x1

2.7 Get the number of fields in the hash table

hlen hash名称

For example

hlen myhash

2.8 Determine whether the specified field in the hash exists

hexists hash名称 key值

For example

hexists myhash field1

2.9 Only get all key values

hkeys hash名称

For example

hkeys myhash

2.10 Only get all value values

hvals hash名称

For example

hvals myhash

3. Data manipulation

3.1 Increment by one

hincrby hash名称 key值 步长

For example

hincrby myhash num 1

3.2 Decrement by one

hincrby myhash num -1

3.3 Judging existence

The value can be set if it does not exist, and cannot be set if it exists

hsetnx hash表名 key值 value值

For example

hsetnx myhash name zhangsan

Seven, Zset (ordered collection)

1 Introduction

On the basis of set, a value for sorting is added.

2. Basic operation

2.1 Add a value

zadd zset集合名称 排序的标志数字 数据

For example

zadd myset 1 one

2.2 Add multiple values

zadd zset集合名称 排序的标志数字 数据2 排序的标志数字 数据3

For example

zadd myset 2 two 3 three

2.3 Check all values

zrange zset集合名称 起始位置 结束位置

For example

zrange myset 0 -1

3. Sorting operation

data preparation

zadd salary 2500 zhangsan
zadd salary 3000 lisi
zadd salary 1000 wnagwu

3.1 Display all users, from small to large (sort by score if the minimum and maximum values ​​of the range are not known)

zrangebyscore zset集合名称 -inf +inf

For example

zrangebyscore salary -inf +inf

3.2 Display all users, from largest to smallest

zrevrange zset集合名称 0 -1

For example

zrevrange salary 0 -1

3.3 Show all users with grades

zrangebyscore zset集合名称 -inf +inf withscores

For example

zrangebyscore salary -inf +inf withscores

3.4 Display the ascending order of employees whose salary is less than 2500 (when a certain value is known as the maximum value of the range)

zrangebyscore zset集合名称 -inf 范围最大值 withscores

For example

zrangebyscore salary -inf 2500 withscores

4. Set operation

4.1 Remove the specified element in the sorted set

zrem zset集合名称 数据名

result

zrem salary lisi

4.2 Get the number in the ordered set

zcard zset集合名称

For example

zcard salary

4.3 Get the number of members in the specified interval

zcount zset集合名称 起始范围 结束范围

For example

zcount myset 1 3