how to write setdata() in qsqlquerymodel(QAbstractItemModel)? - c++

Question

I've made myModel using inheritance (QSqlQueryModel) and I
insert column into it. I want insert data of type QString, but I don't know how to do.
QSQlQueryModel is read-only model. To make it read-write, you must subclass it and reimplement setData() and flags().
I want to override these two methods and here is what I've done so far:
dialog.cpp:
this->model = new myModel(this);
model->setQuery("SELECT * lists");
model->insertColumn(3);
model->setHeaderData(3, Qt::Horizontal, QObject::tr("string"));
qDebug() << model->setData(model->index(0,3),"string",Qt::EditRole);
// column add, column set data using setdata()
ui->tvGameList->setModel(model);
myModel.h:
class myModel : public QSqlQueryModel
{
Q_OBJECT
public:
myModel(QObject *parent = 0);
Qt::ItemFlags flags(const QModelIndex &index) const Q_DECL_OVERRIDE;
bool setData(const QModelIndex &index, const QVariant &value, int role) Q_DECL_OVERRIDE;
};
myModel.cpp:
#include "mymodel.h"
#include <QSqlQuery>
myModel::myModel(QObject *parent): QSqlQueryModel(parent)
{
}
Qt::ItemFlags myModel::flags(const QModelIndex &index) const
{
Qt::ItemFlags flags = QSqlQueryModel::flags(index);
if (index.column() == 1 || index.column() == 2)
flags |= Qt::ItemIsEditable;
return flags;
}
bool myModel::setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole)
{
if (index.isValid() && role == Qt::EditRole)
{
// I don't know here
emit dataChanged(index, index);
return true;
}
return false;
}

Answer 1

See Qt examples, setData must call SQL UPDATE statment as usually SQL.
Qt::ItemFlags EditableSqlModel::flags(
const QModelIndex &index) const
{
Qt::ItemFlags flags = QSqlQueryModel::flags(index);
if (index.column() == 1 || index.column() == 2)
flags |= Qt::ItemIsEditable;
return flags;
}
bool EditableSqlModel::setData(const QModelIndex &index, const QVariant &value, int /* role */)
{
if (index.column() < 1 || index.column() > 2)
return false;
QModelIndex primaryKeyIndex = QSqlQueryModel::index(index.row(), 0);
int id = data(primaryKeyIndex).toInt();
clear();
bool ok;
if (index.column() == 1) {
ok = setFirstName(id, value.toString());
} else {
ok = setLastName(id, value.toString());
}
refresh();
return ok;
}
bool EditableSqlModel::setFirstName(int personId, const QString &firstName)
{
QSqlQuery query;
query.prepare("update person set firstname = ? where id = ?");
query.addBindValue(firstName);
query.addBindValue(personId);
return query.exec();
}