Retrun data from the function when it is executed

Question

async function bringData() {
    return new Promise(resolve => {
        setTimeout(() => {
            resolve(con.query('SELECT company, industry FROM my_table', function (err, result) {
                if (err) {
                    console.error(err);
                    throw 'Error getting data from google_businesses table';
                } else {
                    return result;
                }
            }));
        }, 1000);
    });
}

(async () => {
    // return data from brindData function
    let getData = await bringData();
    console.log(getData);
})();

I am calling this function in main but I am always getting error. I am kind of new to node so if please anybody can guide me or is there any other way to do this such that when I have got my result I can return it.

score 1 · Answer 1 · answered May 30 '22 at 12:54

1

Call resolve with the result from your query.The con.query looks like another asynchronous thing:

con.query('...', (err, result) => {
  if (!err)
    resolve(result);
});

answered May 30 '22 at 12:54

Scarysize

4,131
25
37

Santhosh Nagaraj · Accepted Answer · 2022-06-02T04:18:48.277

0

You can try this.

async function bringData() {
  return new Promise((resolve, reject) => {
    con.query('SELECT company, industry FROM my_table', (err, result) => {
      if (err) {
        reject(err);
      }
      resolve(result);
    })
  });
}


(async () => {
    // execute bringData function
    try {
      let getData = await bringData();
      console.log(getData);
    } catch (e) {
      console.error(e);
    }
     
    
})();

Edited with timeout

async function bringData() {
  return new Promise((resolve, reject) => {
    con.query('SELECT company, industry FROM my_table', (err, result) => {
      if (err) {
        reject(err);
      }
      resolve(result);
    })
  });
}

function timeout(seconds = 10) {
  return new Promise(resolve => {
    setTimeout(resolve, 10 * 1000)
  })
}


(async () => {
    // execute bringData function
    try {
      await timeout();
      let getData = await bringData();
      console.log(getData);
    } catch (e) {
      console.error(e);
    }
})();

edited Jun 02 '22 at 04:18

answered May 30 '22 at 12:54

Santhosh Nagaraj

106
5

Its's right but what if I want ot give a timeout in function. – HumzaXSN May 30 '22 at 13:16
Is giving timeout or waiting for result a requirement ? – Santhosh Nagaraj May 31 '22 at 04:17
Yes it is the requirement as I have to wait my DB to setup. – HumzaXSN May 31 '22 at 06:08
Okay, in that case add I have added the edited with timeout code. You might want to wait before you execute the sql query. Just consider it as a thought, if it is a REST API you would need to have the DB setup before taking in requests or else you will have weird issues. – Santhosh Nagaraj Jun 02 '22 at 04:21

Retrun data from the function when it is executed

2 Answers2