Can't get value from mysql result using Express/Node

Question

I'm working on a pluralsight module for authentication and I'm stuck at the point of actually trying to authenticate users.

connection.query('SELECT * FROM users WHERE username LIKE ?', [data.username], function (err, results) {
    if (err) throw err;
    var results=(JSON.stringify(results));
    console.log(results);
    console.log(results.password)
    if(results.password === password){
        var user = results;
        // done(null, user);
    } else {
        console.log('else')
        // done('Bad password', null)
    }
});

I have this mysql query which looks up the record corresponding to the username and then returns an err or results. I've used JSON.stringify to convert the initial result:

[ RowDataPacket { id: 12, username: 'qqq', password: 'qqq' } ]

To this:

[{"id":12,"username":"qqq","password":"qqq"}]

But results.username and results.password bot are undefined. So it looks to me that the stringyfied results is an array with an object in it.

But when I do

console.log(results[0].username);
console.log(results[0].password);

They are still undefined. So how do I store the username/password inside a variable?

Did you try using a for loop to loop through all the returned results? — Derek Pollard
– Derek Pollard, Commented Aug 16, 2016 at 21:32
For some reason when I do `console.log(results.length) the result is 45 and with a for loop it counts to 45. — Peter Boomsma
– Peter Boomsma, Commented Aug 16, 2016 at 21:46

Derek Pollard · Accepted Answer · 2016-08-16 21:54:30Z

1

Try looping through the result set like this:

for (var i = results.length - 1; i >= 0; i--) {
    var current = results[i];
    console.log(current);
}

Then if all goes well, you should be able to check each variable with: current.username etc..

answered Aug 16, 2016 at 21:54

Derek Pollard

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3 Comments

Peter Boomsma Over a year ago

Ah the stringify "screwed" me over. I was wondering how my for loop would count the exact number of symbols in the string. This was rather stupid. But I'll leave it here anyway. Thanks for pointing out my mistake.

Derek Pollard Over a year ago

No problem! Sometimes it just takes a second set of eyes, we've all been there lol.

Peter Boomsma Over a year ago

To point out how your code is working, the for loop loops through all the objects in the results array and since the result array has only one object it pushes that object into the current var.

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