node.js node-mysql query not working

Question

When querying the DB, I get this error:

TypeError: Cannot call method 'query' of undefined
    at Object.<anonymous> (/home/nodeuser/myapp_node/index.js:51:17)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:901:3

My code looks like:

var mysql = require('mysql');
var mysqlConnection = mysql.createConnection({
  host     : 'localhost',
  user     : 'root',
  password : '',
  database : 'carousel',
  debug : true,
}).connect(function(err) {
    if ( !err ) {
        console.log("Connected to MySQL");
    } else if ( err ) {
        console.log(err);
    }
});


var userId = 23

mysqlConnection.query('SELECT * FROM tusers WHERE id = ?', [userId], function(err, results) {
    console.log(err);
    console.log(results);
});

I made sure "mysql" is in node_modules. Also, I see "Connected to MySQL" in the console.

Do you know how I can make this work?

Brett · Accepted Answer · 2013-10-28 07:04:46Z

5

The connect method that you have chained onto mysql.createConnection does not return a connection. Instead you can do:

var mysqlConnection = mysql.createConnection({
  host     : 'localhost',
  user     : 'root',
  password : '',
  database : 'carousel',
  debug : true,
});

mysqlConnection.connect(function(err) {
  if ( !err ) {
    console.log("Connected to MySQL");
  } else if ( err ) {
    console.log(err);
  }
});

Or you can leave out the connect call altogether "a connection can also be implicitly established by invoking a query" - https://github.com/felixge/node-mysql#establishing-connections

answered Oct 28, 2013 at 7:04

Brett

3,8853 gold badges26 silver badges28 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Lee Loftiss · Accepted Answer · 2013-10-28 06:43:18Z

0

I think the problem is that mysql is working on making the connection in the initialization process but your code is trying to use mysqlConnection before it is ready.

You should put your search in the spot where it says the connection is good.

Also. I think you should look at using a pool. Making a fresh connection each time is quite time consuming.

answered Oct 28, 2013 at 6:43

Lee Loftiss

3,2257 gold badges50 silver badges75 bronze badges

3 Comments

Dan P. Over a year ago

I modified the code to use pool, and it started working. Maybe the pool connection is faster. Is there a way to do this synchronously?

Lee Loftiss Over a year ago

I'm not sure how that could be done. What is it you are trying to achieve?

Lee Loftiss Over a year ago

Here is a dB module I built for a project. Perhaps it will give you some ideas about how to organize things: kleelof.com/db.zip

Collectives™ on Stack Overflow

node.js node-mysql query not working

2 Answers 2

Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related