This package provides support for the RedisJSON module, which adds JSON as a native data type to Redis.
Should be used with redis
/@redis/client
.
For a complete example, see managing-json.js
in the examples folder.
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
":
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.
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 }
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
});