Pool getConnection undefined - node.js

Question

The problem is when I tried the pool connection via variable I'm getting following error
TypeError: sourCon.sourceDBConnection.getConnection is not a function
but if I try the normal connection it's fine.
The code is as follows:
File. ./db/source_db.js
module.exports =
{
sourceDBConnection: function () {
return mysql.createPool({
connectionLimit : 10,
host : 'localhost',
user : 'root',
password : '',
database : 'testdb'
});
}
};
File: app.js
app.get('/report-url', function (req, res) {
corporateModel.DetailReport(dateTime(),request);
})
File. ./models/corporate.js
var sourCon = require("../common_config/source_db");
module.exports =
{
DetailReport: function (dateTime,request,Q) {
var whereTripQueryAppend = "";
sourCon.sourceDBConnection.getConnection(function(err, finConnection) {
/* Get the last inserted ID */
finConnection.query("SELECT student_id FROM studen LIMIT 1", function (error, lastResults, fields) {
/* some process here */
})
})
})
}
Do you know why it works for the normal connection and it's not working for the pool connections? Also if I defined the connection in the same file it works fine. AS
File. ./models/corporate.js
var sourceDBConnection = mysql.createPool({
connectionLimit : 10,
host : 'localhost',
user : 'root',
password : '',
database : 'testdb'
});
var sourCon = require("../common_config/source_db");
module.exports =
{
DetailReport: function (dateTime,request,Q) {
var whereTripQueryAppend = "";
sourceDBConnection.getConnection(function(err, finConnection) {
/* Get the last inserted ID */
finConnection.query("SELECT student_id FROM studen LIMIT 1", function (error, lastResults, fields) {
/* some process here */
})
})
})
}