Read

Jump to the Code block for a combined complete example.

Create a document record

The following example demonstrates reading a document record with a JSON helper library. In Aerospike, JSON documents are handled as a Collection Data Type (CDT). A JSON object is equivalent to a map, and a JSON array is equivalent to a list.

In this example, we create the following JSON document:

employees = [{"id": "09", "name": "Nitin", "department": "Finance"},
             {"id": "10", "name": "Jonathan", "department": "Human Resources"},
             {"id": "11", "name": "Caitlin", "department": "Engineering"}]

The JSON document is added to a bin called employees which is of data type list. There are some advantages to holding an entire document in a single bin, rather than spreading out the document’s fields over multiple bins. There is less metadata overhead when namespaces contain fewer, larger bins.

Setup

Import the necessary helpers, create a client connection, and create a key.

const Aerospike = require('aerospike');
const maps = Aerospike.maps

// Define host configuration
let config = {hosts: '127.0.0.1:3000'};

// Create a new write policy
let writePolicy = new Aerospike.WritePolicy({
    key: Aerospike.policy.key.SEND
});

// Create the record key
let key = new Aerospike.Key('test', 'table1', 5);

Prepare the JSON document to be sent to Aerospike.

let employees = [
    {"id": "09", "name": "Nitin", "department": "Finance"},
    {"id": "10", "name": "Jonathan", "department": "Human Resources"},
    {"id": "11", "name": "Caitlin", "department": "Engineering"}
]

console.info("Employees record:\\n", employees);

Write

Write the document to Aerospike.

let bins = { employees };

// Write the record to Aerospike
;(async () => {
    // Establishes a connection to the server
    let client = await Aerospike.connect(config);
    console.info("Connected to server\\n");

    await client.put(key, bins, [], writePolicy);
    console.info("Wrote record to database\\n");

Read

Read the name field from the third record in the map list.

    // Get 'name' field from 3rd employee record
    const ops = [
      maps.getByKey('employees', 'name')
        .withContext((ctx) => ctx.addListIndex(2))
        .andReturn(maps.returnType.VALUE)
    ]
    const result = await client.operate(key, ops)
    console.info('Name of 3rd employee: ', result.bins.employees)


    // Close the connection to the server
    client.close();
})();

Code block

Expand this section for a single code block to read a document record.

const Aerospike = require('aerospike');
const maps = Aerospike.maps

// Define host configuration
let config = {hosts: '127.0.0.1:3000'};

// Create a new write policy
let writePolicy = new Aerospike.WritePolicy({
    key: Aerospike.policy.key.SEND
});

// Create the record key
let key = new Aerospike.Key('test', 'table1', 5);

let employees = [
    {"id": "09", "name": "Nitin", "department": "Finance"},
    {"id": "10", "name": "Jonathan", "department": "Human Resources"},
    {"id": "11", "name": "Caitlin", "department": "Engineering"}
]

console.info("Employees record:\\n", employees);

let bins = { employees };

// Write the record to Aerospike
;(async () => {
    // Establishes a connection to the server
    let client = await Aerospike.connect(config);
    console.info("Connected to server\\n");

    await client.put(key, bins, [], writePolicy);
    console.info("Wrote record to database\\n");

    // Get 'name' field from 3rd employee record
    const ops = [
      maps.getByKey('employees', 'name')
        .withContext((ctx) => ctx.addListIndex(2))
        .andReturn(maps.returnType.VALUE)
    ]
    const result = await client.operate(key, ops)
    console.info('Name of 3rd employee: ', result.bins.employees)


    // Close the connection to the server
    client.close();
})();