Query FHIR Data as a SQL Server Database in Node.js

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

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

Configure FHIR Connectivity for NodeJS

Connectivity to FHIR from NodeJS is made possible through CData Connect Cloud. To work with FHIR data from NodeJS, we start by creating and configuring a FHIR connection.

1. Log into Connect Cloud, click Connections and click Add Connection
2. Select "FHIR" from the Add Connection panel
3. Enter the necessary authentication properties to connect to FHIR.

   Set URL to the Service Base URL of the FHIR server. This is the address where the resources are defined in the FHIR server you would like to connect to. Set ConnectionType to a supported connection type. Set ContentType to the format of your documents. Set AuthScheme based on the authentication requirements for your FHIR server.

   Generic, Azure-based, AWS-based, and Google-based FHIR server implementations are supported.

   Sample Service Base URLs

   • Generic: http://my_fhir_server/r4b/
   • Azure: https://MY_AZURE_FHIR.azurehealthcareapis.com/
   • AWS: https://healthlake.REGION.amazonaws.com/datastore/DATASTORE_ID/r4/
   • Google: https://healthcare.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION/datasets/DATASET_ID/fhirStores/FHIR_STORE_ID/fhir/

   Generic FHIR Instances

   The product supports connections to custom instances of FHIR. Authentication to custom FHIR servers is handled via OAuth (read more about OAuth in the Help documentation. Before you can connect to custom FHIR instances, you must set ConnectionType to Generic.

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

Add a Personal Access Token

If you are connecting from a service, application, platform, or framework that does not support OAuth authentication, you can create a Personal Access Token (PAT) to use for authentication. Best practices would dictate that you create a separate PAT for each service, to maintain granularity of access.

1. Click on your username at the top right of the Connect Cloud app and click User Profile.
2. On the User Profile page, scroll down to the Personal Access Tokens section and click Create PAT.
3. Give your 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, you are ready to connect to FHIR data from Node.js.

Query FHIR from Node.js

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

• server: tds.cdata.com
• port: 14333
• user: a Connect Cloud user (e.g. user@mydomain.com)
• password: the PAT for the above user
• database: The connection you configured for FHIR (FHIR1)

Connect to FHIR data and start executing queries with the code below:

var sql = require('mssql')
var config = {
	server: 'tds.cdata.com',
	port: 14333, 
	user: 'user@mydomain.com', //update me
	password: 'CONNECT_USER_PAT', //update me	
	options: {
		encrypt: true,
		database: 'FHIR1'
	}
}

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

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