& quot; Ошибка: нет подходящей функции или вызова & quot; к моим окнам деструктора

error: no matching function or call to 'MainWindow::~MainWindow()'

Не удается запустить приложение — QtSql, Я не мог найти в Google способ решить эту проблему. Я включил код из файлов моего проекта — mainwindow.cpp, main.cpp а также mainwindow.h, И я также включил SQL в .pro (QT + = Core GUI SQL).

Код:

mainwindow.h:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QtDebug>
#include <QtSql/QSqlDatabase>
#include <QtSql/QSqlTableModel>namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
explicit MainWindow(QWidget *parent = 0);
virtual ~MainWindow();

private:
Ui::MainWindow *ui;
QSqlDatabase db;
QSqlTableModel *model;};

#endif // MAINWINDOW_H

main.cpp:

#include "mainwindow.h"#include <QApplication>

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();

return a.exec();
}

mainwindow.cpp:

#include "mainwindow.h"#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);

db = QSqlDatabase::addDatabase(QString("QMYSQL"));
db.setHostName(QString("LOCALHOST\\MYSQL"));
db.setDatabaseName(QString("testdb"));
db.setUserName(QString("ROOT"));
db.setPassword(QString("PASSWORD"));

db.open();

MainWindow::~MainWindow()   // ERROR
{
db.close();
delete ui;
}

Скомпилировать вывод:

16:34:42: Running steps for project TisbiCourseWork...
16:34:42: Configuration unchanged, skipping qmake step.
16:34:42: Starting: "/usr/bin/make"g++ -c -m64 -pipe -g -Wall -W -D_REENTRANT -DQT_SQL_LIB -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++-64 -I../TisbiCourseWork -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtSql -I/usr/include/qt4 -I. -I. -I../TisbiCourseWork -I. -o main.o ../TisbiCourseWork/main.cpp
g++ -c -m64 -pipe -g -Wall -W -D_REENTRANT -DQT_SQL_LIB -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++-64 -I../TisbiCourseWork -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtSql -I/usr/include/qt4 -I. -I. -I../TisbiCourseWork -I. -o mainwindow.o ../TisbiCourseWork/mainwindow.cpp
../TisbiCourseWork/mainwindow.cpp: In constructor 'MainWindow::MainWindow(QWidget*)':
../TisbiCourseWork/mainwindow.cpp:18:25: error: no matching function for call to 'MainWindow::~MainWindow()'
MainWindow::~MainWindow()
^
../TisbiCourseWork/mainwindow.cpp:18:25: note: candidate is:
In file included from ../TisbiCourseWork/mainwindow.cpp:1:0:
../TisbiCourseWork/mainwindow.h:20:13: note: virtual MainWindow::~MainWindow()
virtual ~MainWindow();
^
../TisbiCourseWork/mainwindow.h:20:13: note:   candidate expects 1 argument, 0 provided
../TisbiCourseWork/mainwindow.cpp:19:1: error: expected ';' before '{' token
{
^
../TisbiCourseWork/mainwindow.cpp:22:1: error: expected '}' at end of input
}