Node.Js : Connecting with SQL database & retrieve data

First node-mysql package should be installed using npm in your project. (make sure you have installed node.js)

It can be done with code npm install mysql 

Lets get in to code,

• Add the "mysql" module to application
  

  var mysql = require("mysql");

  
  
• Creating a connection object for sql connection
  

  var con = mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "",
    database: "tutorialtest"
  });

  
  Note:here you should enter your details for the database such as host, user, password etc.
  
  
• Making the connection with previously created connection object
  

  con.connect(function(err){
    if(err){
      console.log('Error connecting to Db');
      return;
    }
    console.log('Connection established');
  });

  
  In the function the we pass to connect() function we can add things to happen in a successful or unsuccessful connection
  
  
• Creating SQL query
  

  var queryString='SELECT * FROM tblstudents';

  
  
• Passing SQL query and handling function to query() method
  

  con.query(queryString,function(err,rows){
    if(err) throw err;
    console.log('Data received from Db:\n');
    console.log(rows);
  });

  If the query successfully executed it will print the retrieved details otherwise error will be printed in the console
  
  
• End the connection

  con.end();

Here is the complete code for Connecting to SQL database and retrieving data

var mysql = require("mysql");   //add mysql module

// create a connection object to the db
var con = mysql.createConnection({
  host: "localhost",
  user: "root",
  password: "",
  database: "tutorialtest"
});

//connect to database using connection object
con.connect(function(err){
  if(err){
    console.log('Error connecting to Db');
    return;
  }
  console.log('Connection established');
});

//make the SQL quey
var queryString='SELECT * FROM tblstudents';

//execute the query
con.query(queryString,function(err,rows){
  if(err) throw err;

  console.log('Data received from Db:\n');
  console.log(rows);
});

//end the connection
con.end();

Please add a comment if you have some thing to add or something is not clear to you.