How to connect to on-premise Oracle-db using Azure Functions? - oracle

Question

I'm trying to create an Azure Function to connect and query an on-premise Oracle-DB. I can not see that the Oracle Client or an ODBC-driver is installed on the servers to handle this.
Are there any solutions to this using JS or Python?
I have tried using the node-odbc driver, but the server is missing the Oracle client.

Answer 1

Partially answer for connecting to on-premise service like Oracle-db from Azure Functions, there is an existing SO thread How to Azure function configure for Site-to-Site Connectivity? had answered it, which you can refer to. So first, you must make sure networking access to on-premise server available.
Then, if you want to query oracle database via odbc, the oracle odbc driver must be installed on the client-side. However, the oracle odbc driver is a commerce componet, which you need to pay for getting it, and install it manually in Azure Functions. So even you want to use JS or Python to connect it, I think using Java with Oracle jdbc driver is a better solution from Azure Functions to connect Oracle DB to avoid the additional installation.
The other way I thought is to deploy a REST API app as proxy on your on-premise server to handle the query request from Azure Functions with JS or Python to help connecting Oracle DB.

Answer 2

Create and deploy your code to Azure Functions as a custom Docker container using a Linux base image. Install the Oracle client libraries in custom image. Check out my blog on the topic:
https://www.ravitella.com/azure-function-container/

Answer 3

You will need to establish a hybrid connection. see https://learn.microsoft.com/en-us/azure/app-service/app-service-hybrid-connections
Then you can refer to this thread to establish a context:
https://social.msdn.microsoft.com/Forums/en-US/2434fe10-3219-4625-bdbf-b9e96421230b/entity-framework-with-oracle-and-sql
For a nodejs solution, I would add the NPM and install it using Kudu using node-oracledb:
https://oracle.github.io/node-oracledb/doc/api.html#getstarted
// myscript.js
// This example uses Node 8's async/await syntax.
var oracledb = require('oracledb');
var mypw = ... // set mypw to the hr schema password
async function run() {
let connection;
try {
connection = await oracledb.getConnection( {
user : "hr",
password : mypw,
connectString : "localhost/XEPDB1"
});
let result = await connection.execute(
`SELECT manager_id, department_id, department_name
FROM departments
WHERE manager_id = :id`,
[103], // bind value for :id
);
console.log(result.rows);
} catch (err) {
console.error(err);
} finally {
if (connection) {
try {
await connection.close();
} catch (err) {
console.error(err);
}
}
}
}
run();
sample code