- Qt 5.5
- Qt SQL
- Relational Table Model Example
- relationaltablemodel.cpp Example File
- Qt 5.5.1 Reference Documentation

# relationaltablemodel.cpp Example File

relationaltablemodel/relationaltablemodel.cpp

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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 1;
        createRelationalTables();

        QSqlRelationalTableModel model;

        initializeModel(&model);

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

        return app.exec();
    }