relationaltablemodel.cpp Example File

  /****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** "Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
  **
  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  #include <QtWidgets>
  #include <QtSql>

  #include "../connection.h"

  void initializeModel(QSqlRelationalTableModel *model)
  {
      model->setTable("employee");

      model->setEditStrategy(QSqlTableModel::OnManualSubmit);
      model->setRelation(2, QSqlRelation("city", "id", "name"));
      model->setRelation(3, QSqlRelation("country", "id", "name"));

      model->setHeaderData(0, Qt::Horizontal, QObject::tr("ID"));
      model->setHeaderData(1, Qt::Horizontal, QObject::tr("Name"));
      model->setHeaderData(2, Qt::Horizontal, QObject::tr("City"));
      model->setHeaderData(3, Qt::Horizontal, QObject::tr("Country"));

      model->select();
  }

  QTableView *createView(const QString &title, QSqlTableModel *model)
  {
      QTableView *view = new QTableView;
      view->setModel(model);
      view->setItemDelegate(new QSqlRelationalDelegate(view));
      view->setWindowTitle(title);
      return view;
  }

  void createRelationalTables()
  {
      QSqlQuery query;
      query.exec("create table employee(id int primary key, name varchar(20), city int, country int)");
      query.exec("insert into employee values(1, 'Espen', 5000, 47)");
      query.exec("insert into employee values(2, 'Harald', 80000, 49)");
      query.exec("insert into employee values(3, 'Sam', 100, 1)");

      query.exec("create table city(id int, name varchar(20))");
      query.exec("insert into city values(100, 'San Jose')");
      query.exec("insert into city values(5000, 'Oslo')");
      query.exec("insert into city values(80000, 'Munich')");

      query.exec("create table country(id int, name varchar(20))");
      query.exec("insert into country values(1, 'USA')");
      query.exec("insert into country values(47, 'Norway')");
      query.exec("insert into country values(49, 'Germany')");
  }

  int main(int argc, char *argv[])
  {
      QApplication app(argc, argv);
      if (!createConnection())
          return 1;
      createRelationalTables();

      QSqlRelationalTableModel model;

      initializeModel(&model);

      QTableView *view = createView(QObject::tr("Relational Table Model"), &model);
      view->show();

      return app.exec();
  }