Redis Super Detailed Introductory Tutorial (Basic)

Table of contents

1. What is Redis

2. Install Redis

1. Windows system installation

2. Linux system installation 

3. Redis common commands

Four, Redis basic commands

Five, five data structure types

5.1, String type

5.2, List collection type

5.3, Set collection type

5.4, ​​Hash collection type

5.5, Zset ordered collection type

6. Summary

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1. What is Redis

Redis is an open source memory-based key-value pair database. Its main features and functions include:

1. Based on memory, the read and write speed is extremely fast, and it can handle a large number of read and write requests.

2. Support a variety of data structures, such as strings, hashes, lists, sets, ordered sets, etc., with rich data representation capabilities. 3. Support master-slave replication, providing data redundancy and fault recovery capabilities.

4. Persistence is supported, and memory data can be saved to disk.

5. Support transactions, you can execute multiple commands at one time.

6. Rich functions, which can be used in scenarios such as caching and message queues.

The main application scenarios include:

1. Cache common usage scenarios, such as caching query results, hot data, etc., which greatly reduces the database load.

2. Handle a large number of read and write requests, such as access statistics, message queues, etc.

3. Realization of functions such as leaderboards and counters.

4. pub/sub message subscription.

5. QUE planning task

6. Distributed locks, etc.

To sum up, Redis is an in-memory database with extremely high performance. It supports rich data structures and provides functions such as persistence and transactions. It is very suitable for scenarios such as caching and message queues, and is widely used in various large-scale systems. Its high performance and rich features make it one of the important choices for non-relational databases.

2. Install Redis

1. Windows system installation

The Redis official website has stopped maintaining the Windows version. I uploaded it directly to the cloud disk, and you can download it directly:

https://pan.baidu.com/s/1_2vMncYBVI3jKkh9II9Kag?pwd=8hjr

1. After decompression, double-click redis-server.exe to start the server

run successfully 

2. Double-click redis-cli.exe to start the command window

In this way, Redis can be operated on Windows. 

2. Linux system installation 

You can directly read my blog, the steps are complete and detailed: Linux system installation and deployment Redis complete tutorial (detailed explanation with pictures and texts)

3. Redis common commands

1. Redis has 16 databases by default, switch to the second database

select 1

2. View the number of keys in the current database

DBSIZE

3. Set a key as username and value as mike's data

set username mike

4. Get the value whose key is username

get username

5. Get all keys

keys *

6. Clear the current database

flushdb

7. Clear all databases

flushall

Four, Redis basic commands

1. Query whether the key is username exists

exists username

2. Specify the key as username to move to the No. 1 database

move username 1

3. The specified key expires after username10s

expire username 10

4. Check how long the key is username and how long it will expire

 ttl username

5. Check what type the key is username

type username

Five, five data structure types

5.1, String type

1. Set the value of key as name to htt

set name htt

2. Get the value whose key is name

get name

3. The splicing key is the value of name: httstudy

append name study

 4. Get the length of the value whose key is name

strlen name

5. Set the key to the value of view plus 1 

incr view

6. Set key to the value of view minus 1

decr view

7. Set the key to the value of view plus 10

incrby view 10

8. Set the key to the value of view minus 10

decrby view 10

9. Intercept the string whose subscript is between 0-3, for example: abcdef, abcd after interception

getrange name 0 3

10. Replace the string with the subscript 1, for example: abcdef, a000efg after replacement

setrange name 1 000

11. Set the value of key as name to hello, and it will expire after 10s

setex name 10 hello

12. If there is no title whose key is title, the value is set to redis. If it exists, the set fails

setnx title redis

13. Set multiple values ​​​​at once

mset k1 v1 k2 v2 k3 v3

mset user:1:name htt user:1:age 2

14. Get multiple values ​​at once

mget k1 k2 k3

mget user:1:name user:1:age

15. If k1 already exists, then k1 and k4 all fail to be set, refer to the atomic operation of the transaction

msetnx k1 v1 k4 v4

16. If there is no value whose key is username, return nil, and then set it in; if there is a value, get the original value and set a new value

getset username htt

It will be better understood by looking at the picture!

5.2, List collection type

1. Insert a value or multiple values ​​into the head of the list

lpush list 1

2. Insert a value or multiple values ​​at the end of the list

rpush list 4

 

3. Get the specific value through the interval

lrange list 0 -1

4. Remove the first element of the list: 3

lpop list

5. Remove the last element of the list: 4

rpop list

6. Obtain a value in the list by subscript

lindex list 0

7. Get the length of the list

llen list

 8. Remove the specified number of values ​​from the list set, remove one with a value of 2, and match exactly

lrem list 1 2

9. Intercept the element set between subscript 1 and subscript 2 in the list collection, and overwrite the original list collection

ltrim list 1 2

 10. Update the value of subscript 0 in the list set to bbb, if the value of subscript 0 does not exist, an error will be reported

lset list 0 bbb

11. Insert a specific value before or after a specific element (default first)

linsert list BEFORE kkk aaa

linsert list AFTER kkk aaa

5.3, Set collection type

1. Add an element to the set collection

sadd set hello

2. View all elements in the set collection

 smembers set

3. Check whether an element exists in the set collection

sismember set world

 4. Randomly extract 1 element

srandmember set

5. Randomly extract 2 elements

 srandmember set 2

6. Randomly delete an element in the set collection

spop set

7. Move the world element in the set collection to the set2 collection

smove set set2 world

8. Make the difference of the set2 set minus the set set

sdiff set2 set

9. The intersection of set and set2

sinter set set2

10. Set and set2 are combined and deduplicated

sunion set set2

5.4, ​​Hash collection type

1. Store key-value pair data in the hash collection

hset hash username mike

2. Obtain data from the hash collection

hget hash username

3. Add multiple values ​​to the hash collection at the same time

hmset hash username jack age 2

4. Obtain multiple values ​​from the hash collection at the same time

hmget hash username age

5. Obtain all key-value pairs in the hash collection

hgetall hash

6. Delete the key field specified in the hash collection

hdel hash username

7. Get the length of the hash set

hlen hash

8. Determine whether the specified field exists in the hash set

hexists hash username

9. Get all the keys in the hash collection

hvals hash

10. Get all the values ​​in the hash collection

hkeys hash

 11. Specify the increment in the specified hash set

hincrby hash views 1

12. If it does not exist, set the value directly, if it exists, the setting fails

hsetnx hash password 123456

5.5, Zset ordered collection type

1. Add a value

zadd zset 1 first

2. Add multiple values

zadd zset 2 second 3 third 4 four

3. Get all elements in the zset collection

zrange zset 0 -1

4. Sort the elements in the zset collection from small to large, -inf: negative infinity, +inf: positive infinity

zrangebyscore zset -inf +inf

5. Sort from small to large and output key values

zrangebyscore zset -inf +inf withscores

6. Specify the range from negative infinity to 1

zrangebyscore zset -inf 1 withscores

7. Remove the specified elements in the zset collection

zrem zset four

8. View the number of elements in the zset collection

zcard zset

 9. Invert the specified range

zrevrange zset 1 2

6. Summary

The above is the detailed note summary of the Redis introductory tutorial, and the follow-up blog homepage will continue to update the content about Redis!