Skip to main content

Storing and retrieving Nested JSON document

Profile picture for Ajeet Raina
Author:
Ajeet Raina, Former Developer Growth Manager at Redis

JSON(a.k.a JavaScript Object Notation) is a format for sharing data. A JSON object is a key-value data format that is typically rendered in curly braces. When you’re working with JSON, you’ll likely see JSON objects in a .json file, but they can also exist as a JSON object or string within the context of a program.

Nested JSON is a JSON file with a big portion of its values being other JSON objects. Compared with Simple JSON, Nested JSON provides higher clarity in that it decouples objects into different layers, making it easier to maintain.

Example of Nested JSON object​

employee = {
     'name': "Paul",
     'Age': '25',
     'Location': "USA",
     'Address':
        {
          "longitude": "-113.6335371",
          "latitude": "37.1049502",
          "postal code": "90266"
        }
   }

Follow the below steps to understand how nested JSON objects can be imported into Redis database:

Step 1. Run RedisJSON Docker container​

 docker run -p 6379:6379 --name redis-redisjson redislabs/rejson:latest

Step 2. Verify if RedisJSON module is loaded​

 redis-cli
 127.0.0.1:6379> info modules
 # Modules
 module:name=ReJSON,ver=10007,api=1,filters=0,usedby=[],using=[],options=[]
 127.0.0.1:6379>

Step 3. Nested JSON​

Below is a python code for nested JSON document:

 import redis
 import json

 employee = {
     'name': "Paul",
     'Age': '25',
     'Location': "USA",
     'Address':
        {
          "longitude": "-113.6335371",
          "latitude": "37.1049502",
          "postal code": "90266"
        }
   }
 r = redis.StrictRedis()
 r.execute_command('JSON.SET', 'record', '.', json.dumps(employee))
 reply = json.loads(r.execute_command('JSON.GET', 'record'))

Copy the code and save it in a file called employee.py

Step 4. Load Redis Module​

 pip  install rejson

Step 5. Execute the python script​

Execute the below script and ensure that it executes successfully.

 python3 employee.py

Step 6. Verify the JSON objects gets added to Redis​

 redis-cli
 127.0.0.1:6379> JSON.GET record
 "{\"name\":\"Paul\",\"Age\":\"25\",\"Location\":\"USA\",\"Address\":[{\"longitude\":\"-113.6335371\",\"latitude\":\"37.1049502\",\"postal code\":\"90266\"}]}"

Step 7. Fetching the specific fields​

In case you want to fetch specific filed (like address), then the code would look like this:

 import redis
 import json

 employee = {
     'name': "Paul",
     'Age': '25',
     'Location': "USA",
     'Address':
        {
          "longitude": "-113.6335371",
          "latitude": "37.1049502",
          "postal code": "90266"
        }

  }
 r = redis.StrictRedis()
 r.execute_command('JSON.SET', 'record', '.', json.dumps(employee))
 reply = json.loads(r.execute_command('JSON.GET', 'record', '.Address.longitude'))

Step 8. Verifying the results​

  redis-cli
  127.0.0.1:6379> JSON.GET record .Address.longitude
  "\"-113.6335371\""

References​