relationaltablemodel.cpp Example File

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 #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 EXIT_FAILURE;

     createRelationalTables();

     QSqlRelationalTableModel model;

     initializeModel(&model);

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

     return app.exec();
 }