https://github.com/manjeshpv/node-express-passport-mysql/issues/6

Author: Parken_Vikas

config/passport.js

@@ -8,8 +8,9 @@ var mysql = require('mysql');
 var bcrypt = require('bcrypt-nodejs');
 var dbconfig = require('./database');
 var connection = mysql.createConnection(dbconfig.connection);
-
+connection.connect();
 connection.query('USE ' + dbconfig.database);
+connection.end();
 // expose this function to our app using module.exports
 module.exports = function(passport) {
 
@@ -26,9 +27,11 @@ module.exports = function(passport) {
 
     // used to deserialize the user
     passport.deserializeUser(function(id, done) {
+        connection.connect();
         connection.query("SELECT * FROM users WHERE id = ? ",[id], function(err, rows){
             done(err, rows[0]);
         });
+        connection.end();
     });
 
     // =========================================================================
@@ -48,6 +51,7 @@ module.exports = function(passport) {
         function(req, username, password, done) {
             // find a user whose email is the same as the forms email
             // we are checking to see if the user trying to login already exists
+            connection.connect();
             connection.query("SELECT * FROM users WHERE username = ?",[username], function(err, rows) {
                 if (err)
                     return done(err);
@@ -62,14 +66,16 @@ module.exports = function(passport) {
                     };
 
                     var insertQuery = "INSERT INTO users ( username, password ) values (?,?)";
-
+                    connection.connect();
                     connection.query(insertQuery,[newUserMysql.username, newUserMysql.password],function(err, rows) {
                         newUserMysql.id = rows.insertId;
 
                         return done(null, newUserMysql);
                     });
+                    connection.end();
                 }
             });
+            connection.end();
         })
     );
 
@@ -88,6 +94,7 @@ module.exports = function(passport) {
             passReqToCallback : true // allows us to pass back the entire request to the callback
         },
         function(req, username, password, done) { // callback with email and password from our form
+            connection.connect();
             connection.query("SELECT * FROM users WHERE username = ?",[username], function(err, rows){
                 if (err)
                     return done(err);
@@ -102,6 +109,7 @@ module.exports = function(passport) {
                 // all is well, return successful user
                 return done(null, rows[0]);
             });
+            connection.end();
         })
     );
 };