I want to create such a application in which my iPhone will have the UI for entering the data for the employees. After clicking on the post button data should be saved on the sqlite database and I also want to retrieve the data on button click from the database. I want to use node.js for communicating between my iOS app and the database. Since I have never used node.js before, please give me some links where I can study the sample applications.
I am not an iOS developer but I would make a REST service in Node.js that can sit between your Iphone app and your database. You most likely are going to want to have some form of authentication on the service.
Also does it have to be sqlite? There are databases that can understand HTTP. If you use CouchDB (there are others) you can let your app talk directly to your database. That means you can leave out Node.js completely. You can go even further and use a service that will provide a back-end for you. Something like parse.com (there are others) will do this for you.