Query JSON Services as a SQL Server Database in Node.js

You can use CData Connect AI to query JSON services through a SQL Server interface. Follow the procedure below to create a virtual database for JSON in Connect AI and start querying using Node.js.

CData Connect AI provides a pure MySQL, cloud-to-cloud interface for JSON, allowing you to easily query live JSON services in Node.js — without replicating the data to a natively supported database. As you query data in Node.js, CData Connect AI pushes all supported SQL operations (filters, JOINs, etc) directly to JSON, leveraging server-side processing to quickly return JSON services.

Configure JSON Connectivity for NodeJS

Connectivity to JSON from NodeJS is made possible through CData Connect AI. To work with JSON services from NodeJS, we start by creating and configuring a JSON connection.

1. Log into Connect AI, click Sources, and then click Add Connection

2. Select "JSON" from the Add Connection panel

3. Enter the necessary authentication properties to connect to JSON.

   See the Getting Started chapter in the data provider documentation to authenticate to your data source: The data provider models JSON APIs as bidirectional database tables and JSON files as read-only views (local files, files stored on popular cloud services, and FTP servers). The major authentication schemes are supported, including HTTP Basic, Digest, NTLM, OAuth, and FTP. See the Getting Started chapter in the data provider documentation for authentication guides.

   After setting the URI and providing any authentication values, set DataModel to more closely match the data representation to the structure of your data.

   The DataModel property is the controlling property over how your data is represented into tables and toggles the following basic configurations.

   • Document (default): Model a top-level, document view of your JSON data. The data provider returns nested elements as aggregates of data.
   • FlattenedDocuments: Implicitly join nested documents and their parents into a single table.
   • Relational: Return individual, related tables from hierarchical data. The tables contain a primary key and a foreign key that links to the parent document.

   See the Modeling JSON Data chapter for more information on configuring the relational representation. You will also find the sample data used in the following examples. The data includes entries for people, the cars they own, and various maintenance services performed on those cars.

   
4. Click Save & Test
5. Navigate to the Permissions tab in the Add JSON Connection page and update the User-based permissions.

Add a Personal Access Token

When connecting to Connect AI through the REST API, the OData API, or the Virtual SQL Server, a Personal Access Token (PAT) is used to authenticate the connection to Connect AI. It is best practice to create a separate PAT for each service to maintain granularity of access.

1. Click on the Gear icon () at the top right of the Connect AI app to open the settings page.
2. On the Settings page, go to the Access Tokens section and click Create PAT.
3. Give the PAT a name and click Create.
4. The personal access token is only visible at creation, so be sure to copy it and store it securely for future use.

With the connection configured and a PAT generated, you are ready to connect to JSON services from Node.js.

Query JSON from Node.js

The following example shows how to define a connection and execute queries to JSON with the SQL Server module. You will need the following information:

• server: tds.cdata.com
• port: 14333
• user: a Connect AI user (e.g. [email protected])
• password: the PAT for the above user
• database: The connection you configured for JSON (JSON1)

Connect to JSON services and start executing queries with the code below:

var sql = require('mssql')
var config = {
	server: 'tds.cdata.com',
	port: 14333, 
	user: '[email protected]', //update me
	password: 'CONNECT_USER_PAT', //update me	
	options: {
		encrypt: true,
		database: 'JSON1'
	}
}

sql.connect(config, err => { 
    if(err){
        throw err ;
    }
    new sql.Request().query('SELECT * FROM people', (err, result) => {
        console.dir(result)
    })
        
});

sql.on('error', err => {
    console.log("SQL Error: " ,err);
})