Cannot delete an item in MySQL from a model

[pcheng]

I have a qtableview which shows the values of a QSqlModel. Adding an item works fine. When I try to delete an item I get the error "QSqlQuery::value: not positioned on a valid record".

The itemModel is instantiated as follows:

// Setup the Order Items View
    itemModel = new QSqlRelationalTableModel(this);
    itemModel->setTable("orderitem");
    itemModel->setRelation(2, QSqlRelation("products", "ProductID", "ProductName"));
    ui->itemsTableView->setModel(itemModel);
    ui->itemsTableView->setItemDelegate(new QSqlRelationalDelegate(itemModel));
    ui->itemsTableView->setSelectionMode(QAbstractItemView::SingleSelection);
    ui->itemsTableView->setSelectionBehavior(QAbstractItemView::SelectRows);
    ui->itemsTableView->setColumnHidden(1, true);
    ui->itemsTableView->setAlternatingRowColors(true);

// Setup the Order Items View
    itemModel = new QSqlRelationalTableModel(this);
    itemModel->setTable("orderitem");
    itemModel->setRelation(2, QSqlRelation("products", "ProductID", "ProductName"));
    ui->itemsTableView->setModel(itemModel);
    ui->itemsTableView->setItemDelegate(new QSqlRelationalDelegate(itemModel));
    ui->itemsTableView->setSelectionMode(QAbstractItemView::SingleSelection);
    ui->itemsTableView->setSelectionBehavior(QAbstractItemView::SelectRows);
    ui->itemsTableView->setColumnHidden(1, true);
    ui->itemsTableView->setAlternatingRowColors(true);

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The delete button code is as follows:

void addOrder::on_deleteItemPushButton_clicked()
{
    // Delete the selected item
    int index = ui->itemsTableView->currentIndex().row();
    if (!itemModel->removeRow(index))
        qDebug() << itemModel->lastError();
    ui->savePushButton->setEnabled(true);
}

void addOrder::on_deleteItemPushButton_clicked()
{
    // Delete the selected item
    int index = ui->itemsTableView->currentIndex().row();
    if (!itemModel->removeRow(index))
        qDebug() << itemModel->lastError();
    ui->savePushButton->setEnabled(true);
}

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Any ideas on why the delete does not work?

I am thinking that maybe the problem lies in the fact that the table in MySQL is actually a combined primary key rather than a single key. It takes the ProductID and the OrderID as a combo primary key. I am considering this problem because on another class which has a single key parameter the same code works fine. Is it possible to send two values to delete a row?

Thanks,

Pericles