The words written in the front

This paper is compiled from the documents and videos that the author can search by himself. Since the raw materials are all in English (see the reference document at the end of the article for specific materials), there are inevitable understanding errors. Welcome everyone to discuss and point out my mistakes.

JSON is a lightweight data interchange format, and my company uses THIS data format for information exchange between the front and back ends.

Redis is also essential middleware for software development to improve performance.

Putting JSON data into the Redis database is also an inevitable operation.

This is the first article in the series, mainly through Redis to JSON traditional operations, thus leading to Redis JSON this article.

I’ll start with two traditional ways to manipulate JSON data in Redis.

Redis is the traditional way to manipulate JSON

Raw String A pure String

Put JSON data into Redis as a string.

Method of use

# placed JSON
> set tag '{"1":{"tag":"GOAL_SELECT_TAG","execTs":1640676319},"2":{"tag":"GOAL_SELECT_TAG","execTs":1640676319}}'
OK

# get JSON
> get tag
{"1": {"tag":"GOAL_SELECT_TAG"."execTs":1640676319},"2": {"tag":"GOAL_SELECT_TAG"."execTs":1640676319}}
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advantages

  • Small memory footprint

disadvantages

  • JSONKey-level access and modification of data is not supported. usingstringForm, can only be obtained in full

Hash data structure

HASH the JSON data into Redis.

Method of use

# placed JSON
> hset h name zm age 16
2

# get JSON
> hgetall h
name
zm
age
16
> hget h name
zm
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advantages

  • provideJSONKey level access and modification, and the time complexity isO(1)

disadvantages

  • JSONThe value of a key can only be a string or numeric valueHASHIs stored in the same way,JSONData can only have one level and cannot be nested. Such as
{
    "1": {
    "tag": "GOAL_SELECT_TAG"."execTs": 1640676319
    },
    "2": {
    "tag": "GOAL_SELECT_TAG"."execTs": 1640676319}}Copy the code
  • Occupies less memorystringbig

Redis JSON

Redis JSON is one of Redis Modules.

Redis Module

Redis JSON

Just like other Redis data types,

  • Redis JSONA new type that stores data in binary form in nodes of the tree (ReJSON stores the data in binary format in the tree’s nodes). See the actual operation below for details.
  • Redis JSONOffers a range ofAPITo operateThe JSON data.

Redis JSON startup and getting started

Operating environment setup

  • Go to theredis cloudSign up, apply for the free database, and addRedis JSONAs well asRedis SearchtwoModules.
  • Use terminal or client software to connect to the database based on the generated database configuration itemsRedis.

This way, we can perform Redis JSON operations.

At the same time, two bugs were discovered

  • Redis CloudA spelling error in

  • RedClient error

aRedis JSONExample command

JSON.SET key $ '{"foo":"bar", "ans": 42}'
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  • JSON.SETSet:JSONThe command.Redis JSONAll commands need to be prefixed with JSON
  • key: specifickeyThe name
  • $: indicates the root path. In order to obtainJSONKey values at different levels in,JSONHas its own set of query language, seeJSONPath
  • '{"foo":"bar", "ans": 42}': JSON string

The Redis JSON command is different from the normal Redis command in that there is a Path. The Path is used to parse JSON data easily and uniformly.

There are at least two standards for JSON paths … which means there is no standard for JSON paths.

Redis JSON command

Common Commands

You are given a JSON data

{
    "1": {
    "tag": "GOAL_SELECT_TAG"."execTs": 1640676319
    },
    "2": {
    "tag": "GOAL_SELECT_TAG"."execTs": 1640676319}}Copy the code
  • Set up theJSON
2022- 01- 10 20:22:44 JSON.SET tag $ '{"1":{"tag":"GOAL_SELECT_TAG","execTs":1640676319},"2":{"tag":"GOAL_SELECT_TAG","execTs":1640676319}}'
OK
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  • The key to1The content of the
2022- 01- 11 21:37:36 JSON. GET the tag $1.
[{"tag":"GOAL_SELECT_TAG"."execTs":1640676319}]
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  • The key to2thetagcontent
2022- 01- 11 21:38:45 JSON. GET the tag $2..tag
["GOAL_SELECT_TAG"]

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  • Traversal accesstagValue, returns an array
2022- 01- 10 20:23:01 JSON. GET the tag $.. tag ["GOAL_SELECT_TAG"."GOAL_SELECT_TAG"]
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  • Increase or decrease the key to zero1theexecTsThe numerical
/ / to get
2022- 01- 12 18:34:49 JSON. GET the tag $1.
[{"tag":"GOAL_SELECT_TAG"."execTs":1640676980}]

/ / by 980
2022- 01- 12 18:35:00 JSON. NUMINCRBY tag $1..execTs - 980.
// Latest results
[1640676000]
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Command summary

  • The correspondingJSONDifferent components ofRedis JSONProvide corresponding commands
  • According to the command name you can guess its function, according to the specific needs of each, then refer to the official documentation.

conclusion

  • Redis JSONTo be able to operateJSONData exists.
  • The use of commands is commonRedisThe difference in command is thatPathThe concept of.
  • For better operationJSONThe data,PathIt is unavoidable. You can learnThe use of JSONPath.
  • For aRedisIn addition to functions, the most important thing is the time complexity of commands. But itsThe official documentationThe language is not clear, so this article is to explain, so as not to delay everyone.

This is the first Redis JSON article, and we’ll be looking for more on actual projects, command time complexity, overall performance, and more.

Reference documentation

The official documentation

RedisJSON — pulando JSON como tipo Nativo no Redis

Redis as a JSON store

JSON in Redis – When to use RedisJSON

Redis JSON, from Redis Labs

RedisJSON + RediSearch as a real-time document database, Redis Labs

RedisJSON Explained

RedisJSON: Public Preview & Performance Benchmarking