Can not get the data in response from Azure httpTriggered Function in NodeJS

Question

I am creating a REST API service using Azure Function in nodeJs. The function is reading some data from Azure SQL and I want it to be returned. I am using tedious package to connect to Azure SQL Database.

const { Connection, Request } = require("tedious");

var data = [];
console.log("0." + data);

const config = {
  authentication: {
    options: {
      userName: "------", // update me
      password: "--------" // update me
    },
    type: "default"
  },
  server: "----.database.windows.net", // update me
  options: {
    database: "---", //update me
    encrypt: true
  }
};

module.exports = async function (context, req, resp) {
  const connection = new Connection(config);
  context.bindings.response = { status: 201, body: {"time": new Date().getUTCMinutes(), "data": data} };

  connection.on("connect", err => {
    if (err) {
      console.error(err.message);
    } else {
      queryDatabase(context);         
    }
  });
  
  connection.connect();

  //context.bindings.response = { status: 201, body: JSON.stringify(data) };
        
  function queryDatabase(context) {
    console.log("Reading rows from the Table...");
  
    // Read all rows from table
    const request = new Request(
      `SELECT FirstName, LastName FROM Persons`,
      (err, rowCount, data) => {
        if (err ) {
          console.error(err.message);
        } else {
          console.log(`${rowCount} row(s) returned`);
        }
      }
    );
  
    request.on("row", columns => {
      var row = {};
      
      columns.forEach(column => {
        row[column.metadata.colName] = column.value;
        console.log("%s\t%s", column.metadata.colName, column.value);
          data.push(row);
      });
    });     

    connection.execSql(request);
  }

}

I can read data from Azure SQL Database and the console.log is printing data in the console.

console.log("%s\t%s", column.metadata.colName, column.value);

But while I am trying to bind the data to response, it always shows blank.

{
  "time": 52,
  "data": []
}

How and where to bind the context.bindings.response?

Skin Skin · Accepted Answer · 2022-03-23T20:26:58

If I’ve understood you correctly, try this approach ...

// Construct response
const responseJSON = {
    "name": "Some name",
    "sport": "Some sport",
    "message": "Some message",
    "success": true
}

context.res = {
    // status: 200, /* Defaults to 200 */
    body: responseJSON,
    contentType: 'application/json'
};

Can not get the data in response from Azure httpTriggered Function in NodeJS

1 Answers