@redis/json

@redis/json

This package provides support for the RedisJSON module, which adds JSON as a native data type to Redis. It extends the Node Redis client to include functions for each of the RedisJSON commands.

To use these extra commands, your Redis server must have the RedisJSON module installed.

Usage

For a complete example, see managing-json.js in the Node Redis examples folder.

Storing JSON Documents in Redis

The JSON.SET command stores a JSON value at a given JSON Path in a Redis key.

Here, we'll store a JSON document in the root of the Redis key "mydoc":

import { createClient } from 'redis';

...
await client.json.set('noderedis:jsondata', '$', {
  name: 'Roberta McDonald',
  pets: [
    {
    name: 'Rex',
    species: 'dog',
    age: 3,
    isMammal: true
    },
    {
    name: 'Goldie',
    species: 'fish',
    age: 2,
    isMammal: false
    }
  ]
});

For more information about RedisJSON's path syntax, check out the documentation.

Retrieving JSON Documents from Redis

With RedisJSON, we can retrieve all or part(s) of a JSON document using the JSON.GET command and one or more JSON Paths. Let's get the name and age of one of the pets:

const results = await client.json.get('noderedis:jsondata', {
  path: [
    '.pets[1].name',
    '.pets[1].age'
  ]
});

results will contain the following:

 { '.pets[1].name': 'Goldie', '.pets[1].age': 2 }

Performing Atomic Updates on JSON Documents Stored in Redis

RedisJSON includes commands that can atomically update values in a JSON document, in place in Redis without having to first retrieve the entire document.

Using the JSON.NUMINCRBY command, we can update the age of one of the pets like this:

await client.json.numIncrBy('noderedis:jsondata', '.pets[1].age', 1);

And we can add a new object to the pets array with the JSON.ARRAPPEND command:

await client.json.arrAppend('noderedis:jsondata', '.pets', {
  name: 'Robin',
  species: 'bird',
  age: 1,
  isMammal: false
});