POST /login 500

[zhaobc]

I run the sever is ok at the first time,but when I try to login after a time.That will be "POST /login 500 217.833 ms - 1355".My code:

passport.use(
        'local-login',
        new LocalStrategy({
            // by default, local strategy uses username and password, we will override with email
            usernameField : 'username',
            passwordField : 'password',
            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.query("SELECT * FROM palcan_datacenter.user_tbl WHERE name = ?;",[username],function(err,rows){
                if (err){
                    return done(err);
                }

                if (!rows.length) {
                    return done(null, false, req.flash('loginMessage', 'No user here.')); // req.flash is the way to set flashdata using connect-flash
                }
                
                // if the user is found but the password is wrong
                if (!( rows[0].password == password)){
                    return done(null, false, req.flash('loginMessage', 'Passport is not correct.')); // create the loginMessage and save it to session as flashdata
                }
                var json={};
                json.id=rows[0].uid;
                json.name=rows[0].name;
                json.password=rows[0].password;
                return done(null, json);
            });
        })
    );`
```