TypeError: Database is not a constructor when initializing constructor

Question

I have a Database object (database.js) that looks like this:

//create the database 
function Database(host, dbuser, dbpassword){
    this.host = host;
    this.dbuser = dbuser;
    this.dbpassword = dbpassword;
    this.connection = null;
}

Database.prototype = {
    connection: function(){
        this.connection = mysql.createConnection({
            host: host,
            user: dbuser
        });
    },
    createDatabase: function(){...};

I'm then importing this object into my main app.js using a require statement

var db = require('./database.js');

However, when I try to construct my database object, I get a TypeError Database is not a constructor

var connection = new db('localhost','root');
connection.connection();

What am I doing wrong here? I read up on prototypes and it seems that I'm not lacking anything in that department so it seems that it has something to do with my require statement?

Because node.js support ES6 by default now, use class. It will makes your code easier and you gonna avoid errors like this. — Orelsanpls
– Orelsanpls, Commented Sep 25, 2017 at 15:43
But is there any reason this prototype wont work? I'd have to read up on classes but I thought prototypes were still supported... — dankqheed
– dankqheed, Commented Sep 25, 2017 at 15:45
{host: host, user: dbuser} → {host: this.host, user: this.dbuser} — Namaskar
– Namaskar, Commented Sep 25, 2017 at 15:52

Orelsanpls · Accepted Answer · 2017-09-25 15:52:57Z

2

To export your Database "class" use

module.exports = Database;

And to use

var Database = require('./database.js');

new Database(...);

Here you have a good tutorial about how to use export/require

Is still strongly recommend to upgrade to ES6.

answered Sep 25, 2017 at 15:52

Orelsanpls

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1 Comment

dankqheed Over a year ago

Ahh thank you so much! Worked perfectly! Still iffy on the workings on Node but this seemed to fix my problem

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