pick connection from pool before transaction

functions/methods.ts

@@ -3,12 +3,13 @@ import dbconn = require('../config/dbconn')
 var methods = {
     // ===================== user db =====================
     registerNewUser: function(data:any, callback:any) {
-        dbconn.user.beginTransaction(function(err:any) { // START TRANSACTION
+	dbconn.user.getConnection(function(err:any, thisconn){
+            thisconn.beginTransaction(function(err:any) { // START TRANSACTION
                 if (err) { throw err }
                  // insert profile
-            dbconn.user.query('INSERT INTO user SET ?', data.profile, function (err:any, results:any, fields:any) {
+                thisconn.query('INSERT INTO user SET ?', data.profile, function (err:any, results:any, fields:any) {
                     if (err) {
-                  return dbconn.user.rollback(function() {
+                      return thisconn.rollback(function() {
                         throw err
                       });
                     }
@@ -18,9 +19,9 @@ var methods = {
                         user_id: newUserId,
                         password: data.password
                     }
-                dbconn.user.query('INSERT INTO credential SET ?', credentialData, function (err:any, results:any, fields:any) {
+                    thisconn.query('INSERT INTO credential SET ?', credentialData, function (err:any, results:any, fields:any) {
                         if (err) {
-                        return dbconn.user.rollback(function() {
+                            return thisconn.rollback(function() {
                                 throw err
                             });
                         }
@@ -30,9 +31,9 @@ var methods = {
                             role_id: 2,     // USER
                             user_id: newUserId
                         }
-                    dbconn.user.query('INSERT INTO user_project_role SET ?', projectRoleData, function (err:any, results:any, fields:any) {
+                        thisconn.query('INSERT INTO user_project_role SET ?', projectRoleData, function (err:any, results:any, fields:any) {
                             if (err) {
-                            return dbconn.user.rollback(function() {
+                                return thisconn.rollback(function() {
                                     throw err
                                 });
                             }
@@ -41,16 +42,16 @@ var methods = {
                                 user_id: newUserId,
                                 token: data.verificationToken
                             }
-                        dbconn.user.query('INSERT INTO verification SET ?', verificationData, function (err:any, results:any, fields:any) {
+                            thisconn.query('INSERT INTO verification SET ?', verificationData, function (err:any, results:any, fields:any) {
                                 if (err) {
-                                return dbconn.user.rollback(function() {
+                                    return thisconn.rollback(function() {
                                         throw err
                                     });
                                 }
                                 // COMMIT
-                            dbconn.user.commit(function(err:any) {
+                                thisconn.commit(function(err:any) {
                                     if (err) {
-                                    return dbconn.user.rollback(function() {
+                                        return thisconn.rollback(function() {
                                             throw err
                                         })
                                     }
@@ -60,6 +61,8 @@ var methods = {
                     });
                 });
                 callback(err)
+	    });
+            callback(err)
         })
     },
     getUserByEmail: async function(email:any) {