QSqlDatabase Example

/************************/
/****  mainwindow.h  ****/
/************************/

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QSqlDatabase>

class QFileDialog;

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    QAction         *newFileAction;
    QAction         *openFileAction;
    QAction         *quitAction;
    QMenuBar        *menuBar;
    QMenu           *fileMenu;

    QFileDialog     *fileDialog;

    const QStringList fileFilters { "SQLite3 files (*.sqlite)",
                                    "Any files (*)"};
private slots:
    void newFile();
    void openFile();

};
#endif // MAINWINDOW_H


/************************/
/***  mainwindow.cpp  ***/
/************************/

#include <QMenuBar>
#include <QSqlQuery>
#include <QFileDialog>
#include <QUuid>

#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    setWindowTitle( "database" );
    setMinimumSize( 800, 600 );
    newFileAction = new QAction( "&New", this );
    openFileAction = new QAction( "&Open", this );
    quitAction = new QAction( "&Quit", this );
    menuBar = new QMenuBar();
    setMenuBar( menuBar );
    fileMenu = menuBar->addMenu( "&File" );
    fileMenu->addAction( newFileAction );
    fileMenu->addAction( openFileAction );
    fileMenu->addAction( quitAction );

    connect( newFileAction, &QAction::triggered, this, &MainWindow::newFile );
    connect( openFileAction, &QAction::triggered, this, &MainWindow::openFile );
    connect( quitAction, &QAction::triggered, this, &MainWindow::close );

    fileDialog = new QFileDialog( this );
    fileDialog->setWindowModality( Qt::WindowModal );
    fileDialog->setFileMode( QFileDialog::AnyFile );
    //dialog->setOption( QFileDialog::DontUseNativeDialog );
    fileDialog->setDefaultSuffix( "sqlite" );
    fileDialog->setNameFilters( fileFilters );
}

MainWindow::~MainWindow() {}

void MainWindow::newFile()
{
    fileDialog->setAcceptMode(QFileDialog::AcceptSave);
    if ( fileDialog->exec() == QDialog::Accepted )
    {
        QString dbName = fileDialog->selectedFiles().constFirst();
        QSqlDatabase db = QSqlDatabase::database();
        db.setDatabaseName( dbName );
        if ( db.open() )
        {
            QSqlQuery query;
            query.exec( "CREATE TABLE example (id TEXT PRIMARY KEY)" );
            QString q = "INSERT INTO example (id) VALUES('" +
                         QUuid::createUuid().toString() +
                        "')";
            //qDebug() << q;
            query.exec( q );
            qDebug() << "New Database: " << dbName;
            query.exec( "SELECT * FROM example" );
            while (query.next()) {
                qDebug() << query.value(0).toString();
            }
        }
    }
}

void MainWindow::openFile()
{
    fileDialog->setWindowTitle( "Open file" );
    fileDialog->setAcceptMode( QFileDialog::AcceptOpen );
    if ( fileDialog->exec() == QDialog::Accepted )
    {
        QString dbName = fileDialog->selectedFiles().constFirst();
        QSqlDatabase db = QSqlDatabase::database();
        db.setDatabaseName( dbName );
        if ( db.open() )
        {
            QSqlQuery query;
            QString q = "INSERT INTO example (id) VALUES('" +
                        QUuid::createUuid().toString() +
                        "')";
            query.exec( q );
            qDebug() << "Database: " << dbName;
            query.exec( "SELECT * FROM example" );
            while (query.next()) {
                qDebug() << query.value(0).toString();
            }
        }
    }
}

/************************/
/******  main.cpp  ******/
/************************/

#include "mainwindow.h"

#include <QApplication>
#include <QSqlDatabase>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QSqlDatabase db = QSqlDatabase::addDatabase( "QSQLITE" );
    MainWindow w;
    w.show();
    return a.exec();
}


/************************/
/**** CMakeLists.txt ****/
/************************/

cmake_minimum_required(VERSION 3.16)

project(db VERSION 0.1 LANGUAGES CXX)

set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(QT NAMES Qt6 Qt5 REQUIRED COMPONENTS Widgets Sql)
find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Widgets Sql)

set(PROJECT_SOURCES
        main.cpp
        mainwindow.cpp
        mainwindow.h
)

if(${QT_VERSION_MAJOR} GREATER_EQUAL 6)
    qt_add_executable(db
        MANUAL_FINALIZATION
        ${PROJECT_SOURCES}
    )
# Define target properties for Android with Qt 6 as:
#    set_property(TARGET db APPEND PROPERTY QT_ANDROID_PACKAGE_SOURCE_DIR
#                 ${CMAKE_CURRENT_SOURCE_DIR}/android)
# For more information, see https://doc.qt.io/qt-6/qt-add-executable.html#target-creation
else()
    if(ANDROID)
        add_library(db SHARED
            ${PROJECT_SOURCES}
        )
# Define properties for Android with Qt 5 after find_package() calls as:
#    set(ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/android")
    else()
        add_executable(db
            ${PROJECT_SOURCES}
        )
    endif()
endif()

target_link_libraries(db PRIVATE Qt${QT_VERSION_MAJOR}::Widgets
                                        Qt${QT_VERSION_MAJOR}::Sql)

# Qt for iOS sets MACOSX_BUNDLE_GUI_IDENTIFIER automatically since Qt 6.1.
# If you are developing for iOS or macOS you should consider setting an
# explicit, fixed bundle identifier manually though.
if(${QT_VERSION} VERSION_LESS 6.1.0)
  set(BUNDLE_ID_OPTION MACOSX_BUNDLE_GUI_IDENTIFIER com.example.db)
endif()
set_target_properties(db PROPERTIES
    ${BUNDLE_ID_OPTION}
    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
    MACOSX_BUNDLE TRUE
    WIN32_EXECUTABLE TRUE
)

include(GNUInstallDirs)
install(TARGETS db
    BUNDLE DESTINATION .
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
)

if(QT_VERSION_MAJOR EQUAL 6)
    qt_finalize_executable(db)
endif()