Nodejs retrieving information from database and passing to JavaScript

Question

I am writing a simple application which is running on Nodejs. I am using centos. Front end is html and JavaScript. In the HTML page, I have 2 forms. On selection of data from form1 and clicking on a button, a table has to be loaded inside form2. I have managed to do this functionality with JavaScript. (For now I have used hard coded values.) If I were to retrieve values from database, how should I proceed? I am a noob in Nodejs ! I am processing all the requests using similar methods as below:

app.post('/DomainInfo', function (req, res) {
console.log("POST: ");
DOMAIN = req.body.DomainName;
LOCALE = req.body.locale;
connection.query('insert into DomainInterval ( Domain , Locale , ASRFrequency ,     NLUFrequency, Numinstances ) values (' + "'" + DOMAIN + "'" + ',' + "'" + LOCALE + "'" + ",'" + ASRFRQ + "'" + ',' + "'" + NLUFRQ + "'" + ',' + NONODES + ');', function (error, rows, fields) {

    res.writeHead(200, {
        'Content-Type': 'text/plain'
    });
    res.end('record inerted...');
 });
  connection.query('commit;');
  console.log('success!');
});


// Launch server
app.listen(1213);

While calling these methods, the data retrieved form database is displayed on a separate page. I want it to be sent to the same html page from where the request was sent, sort of like an AJAX call. Is there any way to do this without PHP or servlet?

are you using express? if so pls mention it

Mithun Satheesh
– Mithun Satheesh

2013-11-21 04:55:22 +00:00
Commented Nov 21, 2013 at 4:55 — Mithun Satheesh
– Mithun Satheesh, Commented Nov 21, 2013 at 4:55

Mithun Satheesh · Accepted Answer · 2013-11-21 05:07:55Z

3

If i were to retrieve values from database , How should i proceed ?

find an appropriate database and figure out the best driver for it. here are some

mongodb : node-mongodb-native.
mysql : node-mysql

Sort of like an AJAX call . Is there any way to do this without php or servlet ?

from your code you seem to use express framework. to make ajax calls, you just need to make a route specific for the ajax target and give the same in your client side ajax request.

its as simple as:

node.js

app.post('/ajaxTarget', function (req, res) {
    //get data from database and return data like
    res.json(data);    
});

client side

//assuming you are using jquery
$.post("/ajaxTarget",function(data){
    //process the data
});

answered Nov 21, 2013 at 5:07

Mithun Satheesh

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7 Comments

Rasika Vijay Over a year ago

Hi thanks . I am using node-mysql and express framework. In the client side , I am using javascript and not jquery . Is there any way to receive the ajax result with javascript

Mithun Satheesh Over a year ago

@rasikavijay: definitely possible. i just put the jquery example as it was a one liner plus no fear of browser compactibilities. :)

Rasika Vijay Over a year ago

Thanks .One more Doubt . The data being retrieved from database has to be formatted to a json format and then sent ? Can you please send any tutorial link encompassing the above information .?

Mithun Satheesh Over a year ago

the data retrieved from query should be a JavaScript object, so you can pass it directly into res.json(yourObj);

Rasika Vijay Over a year ago

Hi. I m still at a loss on how to process the response. I have given my complete problem and code in this link . Please review and suggest link

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Nodejs retrieving information from database and passing to JavaScript

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If i were to retrieve values from database , How should i proceed ?

Sort of like an AJAX call . Is there any way to do this without php or servlet ?

node.js

client side

7 Comments

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1 Answer 1

If i were to retrieve values from database , How should i proceed ?

Sort of like an AJAX call . Is there any way to do this without php or servlet ?

node.js

client side

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