use to undeclared identifier on SQL Connecting

[ELEMENTICY]

Hi,i need help.
I got error "use to undeclared identifier" on my code,and im stuck on it.Please help me,im new to QT.Thank You = )\

Here is the code:

#include "login.h"
#include "ui_login.h"
#include "dialog.h"
#include <QSqlRecord>

QSQLITE::DB db;

Login::Login(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::Login)
{
    ui->setupUi(this);
    db = QSqlDatabase::addDatabase("QSQLITE");
    db.setHostName("localhost");
    db.setDatabaseName("login_system");
    db.setUserName("root");
    db.setPassword("");

    if(db.open())
        ui->label_4->setText("Connected...");
    else
        ui->label_4->setText("Disconnected...");
}

Login::~Login()
{
    delete ui;
}

void Login::on_pushButton_clicked()
{
    QString username,password;
    username = ui->lineEdit_username->text();
    password = ui->lineEdit_2_password->text();

    if(!db.open())
    {
        qDebug()<<"Not Connected to DataBase";
        return;

    }

    QSqlQuery qry;

    if(qry.exec("select * from login where username ='"+ username +"' and password='"+password +"'"))
    {
    int count=0;
        if(qry.next())
        {
            count++;
        }

        if(count==1){
            ui->label_4->setText("Sucessfully logged in");
            this->hide();
            Dialog dialog;
            dialog.setModal(true);
            dialog.exec();

        }
        if(count>1)
            ui->label_4->setText("Username doesn't seem valid,or the password is wrong.Please try again");
        if(count<1)
            ui->label_4->setText("Username doesn't seem valid,or the password is wrong.Please try again");


    }
}

The error is appear on line 6: "QSQLITE::DB db;"

[Christian Ehrlicher]

@ELEMENTICY said in use to undeclared identifier on SQL Connecting:

QSQLITE::DB db;

So what should this be? Please read the documentation on how to open a db connection.

[Christian Ehrlicher]

@ELEMENTICY said in use to undeclared identifier on SQL Connecting:

QSQLITE::DB db;

So what should this be? Please read the documentation on how to open a db connection.

[ELEMENTICY]

@Christian-Ehrlicher i dont know,i could't find the answer in the doc,im new at c++,please tell me answer.
Appreciate it : )

[Christian Ehrlicher]

So I would start with a c++ book instead. And I don't need to provide some code as it is written exactly in the documentation I gave you.

[ELEMENTICY]

@Christian-Ehrlicher ok

[ELEMENTICY]

@Christian-Ehrlicher Doing that is good,but.You didt tell me the answer ;/

[ELEMENTICY]

please help :)

[Christian Ehrlicher]

@ELEMENTICY said in use to undeclared identifier on SQL Connecting:

Doing that is good,but.You didt tell me the answer ;/

I gave the answer to you - my link has a code example which does exactly what you want. See in the details section!