Connecting to database in Express

Question

Trying to connect to database using Express

• I am new to Express(I have used NODEJS),
• I am trying to connect to database and display a simple JSON as the resultant output
• I tried the below code

---

var express = require('express')
  , http = require('http');

var app = express();

var connection = mysql.createConnection({
        host: 'localhost',
        user: 'root',
        password: "root",
        database: 'restaurant'
});

// all environments
app.set('port', process.env.PORT || 7002);


app.get('/',function(request,response){
connection.query('SELECT * FROM restaurants', function(err, rows, fields)

        {
                console.log('Connection result error '+err);
                console.log('no of records is '+rows.length);
                        response.writeHead(200, { 'Content-Type': 'application/json'});
                response.end(JSON.stringify(rows));
        });

} );

http.createServer(app).listen(app.get('port'), function(){
  console.log('Express server listening on port ' + app.get('port'));
});

Error::

var connection = mysql.createConnection({
                 ^
ReferenceError: mysql is not defined

---

Error tells mysql module is absent, But i have installed mysql module using::

npm install mysql 

Still no change in error Any ideas

Answer 1

You're missing the mysql module.

var express = require('express')
  , http = require('http')
  , mysql = require('mysql');

But also you need to connect():

connection.connect();

Before you start querying the database.

All-together now for laziness:

var express = require('express')
  , http = require('http')
  , mysql = require('mysql'); // <---- HERE

var app = express();

var connection = mysql.createConnection({
    host: 'localhost',
    user: 'root',
    password: "root",
    database: 'restaurant'
});

connection.connect(); // <---- AND HERE

// all environments
app.set('port', process.env.PORT || 7002);


app.get('/',function(request,response){
connection.query('SELECT * FROM restaurants', function(err, rows, fields)

    {
            console.log('Connection result error '+err);
            console.log('no of records is '+rows.length);
                    response.writeHead(200, { 'Content-Type': 'application/json'});
            response.end(JSON.stringify(rows));
    });

} );

http.createServer(app).listen(app.get('port'), function(){
  console.log('Express server listening on port ' + app.get('port'));
});