here’s the part related to query execution

const sql = require('msnodesqlv8');
const connectionString = "******************************";

function exeQuery(query, params, callback) {
    console.log('Executing query:', query);
    console.log('Query parameters:', params);

    sql.query(connectionString, query, params, (err, result) => {
        if (err) {
            console.error('Error executing query:', err);
            callback(err, null);
        } else {
            console.log('Query executed successfully. Result:', result);
            callback(null, result);
        }
    });
}


module.exports = exeQuery;

and here’s the endpoint

// Route to view mobile logs
router.get('/viewMobileLogs/:mobileNumber', (req, res) => {
    const mobileNumber = req.params.mobileNumber;
    const query = `EXEC [dbo].[GetMobileLog] @MobileNum = ?`;

    exeQuery(query, [mobileNumber], (err, result) => {
        if (err) {
            console.error('Error fetching mobile logs:', err);
            return res.status(500).json({ error: 'Internal Server Error' });
        } else {
            return res.json(result);
        }
    });
});

and here’s the logs:

[nodemon] starting `node app.js`
Server is running on port 3000
Redis Connected Successfully
Executing query: EXEC [dbo].[GetMobileLog] @MobileNum = ?
Query parameters: [ '01639521598' ]
Query executed successfully. Result: []
GET /EmployeeMobiles/viewMobileLogs/01639521598 200 1084.553 ms - 2
Query executed successfully. Result: [
  {
    LDate: 2023-05-05T16:20:00.000Z { nanosecondsDelta: 0 },
    UserName: 'John Doe',
    ActionText: 'New bill added (New Bill)'
  }
]
node:_http_outgoing:652
    throw new ERR_HTTP_HEADERS_SENT('set');
    ^

Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
    at ServerResponse.setHeader (node:_http_outgoing:652:11)
    at ServerResponse.header (C:Usersmohamed.eltananyDesktopemployees_bills_backnode_modulesexpresslibresponse.js:795:10)
    at ServerResponse.send (C:Usersmohamed.eltananyDesktopemployees_bills_backnode_modulesexpresslibresponse.js:175:12)
    at ServerResponse.json (C:Usersmohamed.eltananyDesktopemployees_bills_backnode_modulesexpresslibresponse.js:279:15)
    at C:Usersmohamed.eltananyDesktopemployees_bills_backroutesemployeeMobilesRoutes.js:67:24
    at ChunkyArgs.callback (C:Usersmohamed.eltananyDesktopemployees_bills_backconfiganotherAsyncConnection.js:14:13)
    at C:Usersmohamed.eltananyDesktopemployees_bills_backnode_modulesmsnodesqlv8libsql-client.js:82:18
    at Immediate.<anonymous> (C:Usersmohamed.eltananyDesktopemployees_bills_backnode_modulesmsnodesqlv8libconnection.js:218:9)
    at process.processImmediate (node:internal/timers:478:21) {
  code: 'ERR_HTTP_HEADERS_SENT'
}

Node.js v20.11.0
[nodemon] app crashed - waiting for file changes before starting...

i’m trying to understand why the behaviour occurs as according to the logs firstly the result is [] and based on it the server respond but then the resultSet is here and i get ERR_HTTP_HEADERS_SENT.