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This article mainly introduces the example analysis of redis entry knowledge points, which has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, let the editor take you to understand it.

A preface

Let's first introduce the concept of redis:

Redis is an open source key-value storage system that belongs to NoSQL (Not Only SQL), not just a relational database.

Take a look at the advantages of redis:

Rich data types

Support for key expiration feature

Each instruction is an atomic operation.

Extremely high read and write performance

Get a preliminary understanding of the additional features of redis

Can be primary storage and secondary storage, master-slave replication

Support for persistent data storage

Linux installation redis link: https://www.jianshu.com/p/bc84b2b71c1c

Windows installation redis link: https://www.jianshu.com/p/e16d23e358c0

Docker installation redis Link https://juejin.im/post/5ca59dece51d4508b32a1292

Finally, it is recommended that you install redis 5.0.5 stable version in the production environment.

Two and five basic data types 2.1 strings

String data is stored in the form of key-val (key-value pair), that is, each key has a corresponding unique value; as shown in the following figure, if age is key, the corresponding unique value is 18

The command is described as follows

Get: gets the value that stores the given key

Set: sets the value of a given storage key

Del: deletes the value of a given key

Incr: count, add 1 at a time

Incrby: calculation, addition or subtraction of a given value

Mset: setting multiple key values

Mget: gets the values of multiple given keys

Expire: set expiration time (for all types)

Exists: whether there is a key

Example of storage string

Set key value

127.0.0.1 purl 6379 > set zszxz 666OK

Get string example

Get key

127.0.1 6379 > get zszxz "666"

Delete string exampl

Del key [key...]

127.0.0.1 6379 > del zszxz (integer) 1

Example of counting:

Incr key

127.0.0.1 set age 100OK127.0.0.1:6379 > incr age (integer) 101127.0.0.1 integer 6379 > incr age (integer) 102127.0.0.1 integer 6379 > get age "102" 127.0.1

Incrby key increment

127.0.0.1 set age 100OK127.0.0.1:6379 > incrby age 5 (integer) 105127.0.0.1 integer 6379 > incrby age-2 (integer) 103127.0.1 integer 6379 > get age "103" 127.0.1

Example of multi-key value pair

Mset key value [key value...]

Mget key [key...]

127.0.0.1 you1 6379 > mset U1 you1 U2 you2OK127.0.0.1:6379 > mget U1 U21) "you1" 2) "you2" 127.0.0.1 you2OK127.0.0.1:6379 >

Set expiration time

Expire key seconds

127.0.0.1 expire 6379 > get U1 1 (integer) 1127.0.1 get U1 (nil) 127.0.0.1 get 6379 >

There are examples

Exists key [key...]

127.0.0.1 integer 6379 > set age 100OK127.0.0.1:6379 > exists age (integer) 1127.0.1 VR 6379 > 2.2

A list is actually a linked list. A list has a key, and a key corresponds to multiple values. The values can be repeated. When taking values, you can take values according to the index.

Rpush: push values to the right end of the list

Lrange: gets all the values in the given range of the list

Lindex: gets a single element at a given location on the list

Lpop: a value pops up from the left end of the list

Example of listing values

Rpush key value [value...]

127.0.0.1 rpush list-zszxz 6379 > rpush list-zszxz a (integer) 1127.0.0.1 integer 6379 > rpush list-zszxz c (integer) 3

Example of range value

Lrange key start stop

127.0.0.1 lrange list-zszxz 6379 > 0-11) "a" 2) "b" 3) "c"

Example of a given index value

Lindex key index

127.0.0.1 6379 > lindex list-zszxz 1 "b"

Left pop-up example

Lpop key

127.0.0.1 lpop list-zszxz 6379 > lrange list-zszxz 0-11) "b" 2) "c" 2.3 collection

A collection is similar to a list, except that the collection is unordered and each value is unique and cannot be repeated.

Sadd: adds a given value to the collection

Smembers: returns all the elements of the collection

Sismember: checks whether a given element exists in the collection

Srem: remove the element if it exists in the collection

Add exampl

Sadd key member [member...]

127.0.0.1 sadd set-zszxz 6379 > sadd set-zszxz a (integer) 1127.0.0.1 integer 6379 > sadd set-zszxz c (integer) 1

Returns examples of all elements

Smembers key

127.0.0.1 smembers set-zszxz1 6379) "c" 2) "b" 3) "a"

There are examples

Sismember key member

127.0.0.1 6379 > sismember set-zszxz c (integer) 1

Delete exampl

Srem key member [member...]

127.0.0.1 srem set-zszxz 6379 > smembers set-zszxz1 (a (integer) 1127.0.0.1) smembers set-zszxz1) "c" 2) "b" 2.4 hash

Hash points are like dictionaries in map,python in java; multiple key-value pairs are stored in a hash

Hset: the key-value pair of a given hash

Hget: gets the value of the specified hash key

Hetall: gets the key-value pairs of all hashes

Hdel: if the key exists in the hash, remove the key

Example of setting hash key value pair

Hset key field value

127.0.0.1 hset hash-key key1 6379 > hset hash-key key2 a (integer) 1127.0.0.1 integer 6379 > hset hash-key key3 c (integer) 1127.0.1

Example of getting a hash given key

Hget key field

127.0.0.1 6379 > hget hash-key key1 "c"

Get an example of all hash key-value pairs

Hgetall key

127.0.1 key3 6379 > hgetall hash-key1) "key1" 2) "c" 3) "key2" 4) "b" 5) "key3" 6) "c"

Delete hash key exampl

Hdel key field [field...]

127.0.0.1 hdel hash-key key1 (integer) 1127.0.0.1 hgetall hash-key1) "key2" 2) "b" 3) "key3" 4) "c" 127.0.1 > 2.5 ordered set

The redis ordered set is similar to the hash, except that the key is called member and value is called score. It is sorted according to the score.

Zadd: adds members with a given score to an ordered set

Zrange: gets elements based on the index of an ordered collection

Zrangebyscore: gets all elements within a given score range in an ordered collection

Zrem: if the member exists in an ordered collection, remove it

Add member exampl

Zadd key score member [score member...]

127.0.0.1 zadd zset-key member1 (integer) 1127.0.0.1 member2 (integer) 1127.0.0.1 member2 6379 > zadd zset-key 680 member3 (integer) 1127.0.0.1 integer 6379 >

Gets an example of a member within the specified index range

Zrange key start stop [WITHSCORES]

Without score

127.0.0.1 zrange zset-key 6379 > member3 0-11) "member1" 2) "member2" 3) "member3"

Bring score.

127.0.1 zrange zset-key 6379 > member3 0-1 withscores1) "member1" 2) "600" 3) "member2" 4) "650" 5) "member3" 6) "680"

Gets an example of a member within the specified score range

Zrangebyscore key min max [WITHSCORES] [LIMIT offset count]

127.0.0.1 member1 6379 > zrangebyscore zset-key 600 650 withscores1) "member1" 2) "600" 3) "member2" 4) "650"

Remove member exampl

Zrem key member [member...]

127.0.0.1 zrem zset-key member1 (integer) 1127.0.0.1 withscores1 6379 > zrange zset-key 0-1 withscores1) "member2" 2) "650" 3) "member3" 4) "680" 127.0.1

Shorthand method:

String, key-value

Lists and collections, similar to linked lists, an ordered, an unordered, a key stores multiple values

Hash and ordered sets, similar to dictionaries, map; stores multiple key-value; ordered sets with key as member and value as score, sorted by score

Thank you for reading this article carefully. I hope the article "sample Analysis of introductory knowledge points of redis" shared by the editor will be helpful to you. At the same time, I also hope that you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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