How do I update a row in the model and commit to database?

[jdent]

I want to change a column of a QSqlRecord in a model like this:

	QSqlRecord rec = model->record(0);
	auto val = rec.value(1).toString();
	val += "###";
	rec.setValue(1, val);
	bool ok = model->submitAll();

Is this the correct way?

[jdent]

@jdent No, to affect the model we need to go via the model!

this is the solution:

	QModelIndex index = model->index(0, 1);
	QString v = model->data(index).toString();
	QModelIndex idIndex = index.siblingAtColumn(0);
	int id = model->data(idIndex).toInt();
	v += "???";
	bool ok = model->setData(index, v); // this is required!!!
	ok = model->submit();

[JonB]

@jdent
You do not need to drop down to accessing the model directly via QModelIndex and setData(). You can do it via the QSqlRecord. After you went rec.setValue(1, val); you need to call bool QSqlTableModel::setRecord(int row, const QSqlRecord &values) to transfer the altered in-memory rec to the model:

    QSqlRecord rec = tm.record(0);
    QModelIndex idx = tm.index(0, 3);
    qDebug() << rec.value(3).toString();
    qDebug() << idx.data().toString();
    auto val = rec.value(3).toString();
    val += "###";
    rec.setValue(3, val);
    qDebug() << rec.value(3).toString();
    qDebug() << idx.data().toString();
    tm.setRecord(0, rec);
    qDebug() << rec.value(3).toString();
    qDebug() << idx.data().toString();

This shows the underlying model altered after the tm.setRecord(0, rec); statement. You can then commit() or whatever if you wish.

record() generates a copy of what is in a model row. setRecord() is required if you alter that and want to write it back to the model row.