我没有从module.exports得到答案

Question

db.js

 pool.connect(function (err, client, done) {

client.query('SELECT id, user_id, name  FROM public.chat;', function (err, 
 result) {
    if (err) console.log("error" + err.message);


    else {
        module.exports.res = result.rows[0];
         }
        });

 });

file app.js

 var con = require('./db/connect');

 console.log(con.res);

I'm getting the result undefined ,I don't understand, the reason is callback?

Answer 1

Try this:

db.js:

module.exports = pool.connect(function (err, client, done) {
                   client.query('SELECT id, user_id, name  FROM public.chat;', function (err, result) {

                     if (err) 
                       console.log("error" + err.message);
                     else 
                       return result.rows[0];
                     });
                  });

app.js:

 var con = require('./db/connect');
 console.log(con());