Error: Global connection already exists. Call sql.close() first

Hi I am creating node js restful api by using sqlserver database , i prepare get api when i am using that api output is shown in json format, while refreshing that browser gain its shows "Error: Global connection already exists. Call sql.close() first."error . I am adding code

var express = require("express");

var sql = require("mssql");
var app = express();

//Initiallising connection string
var dbConfig = {
    user: 'sa',
    password: 'India123',
    server: 'localhost',
    database: 'sample'

  
};

app.get('/login', function (req, res) {

    // connect to your database
    
    var data = {

        "user": ""
    };
    sql.connect(dbConfig, function (err) {

        if (err) console.log(err);

 
        var request = new sql.Request();
   
      
        request.query('select * from Login', function (err, result) {

            if (err) console.log(err)

            // send data as a response
            //res.send(result.recordset);
            data["user"] = result.recordset;
            res.send(data);
          
      
        });
    }); 

});

var server = app.listen(5000, function () {
    console.log('Server is running..');
});

Please correct me code . thanks advance

via Naveen Dodda