how to set QComboBox on qsqlquerymodel header

Hi,

I need to show the combobox widget on a qsqlquerymodel header. (in the second column header)
In my code i overrided the headerData() method.
But combobox is not coming.Its showing empty.

My Code,

Code:

---

UserQueryModel *model = new UserQueryModel (ui.table);//derived from qsqlquerymodel class
model->setQuery("select * from sf_search");
ui.table->setModel(model);
 
 
class UserQueryModel:public QSqlQueryModel
{
public:
	QTableView *mTable;
	QVariant variant;
	QWidget widget;
 
UserQueryModel(QTableView *table)
{
	 mTable = table;
 
	QHBoxLayout *layout = new QHBoxLayout(&widget);
	QComboBox *box = new QComboBox(&widget);
	layout->addWidget(box);
	variant.setValue(&widget);
 
}
 
QVariant headerData( int section, Qt::Orientation orientation, int role) const
{
	if(section == 2 && (orientation == Qt::Horizontal))
	{
		return variant;
	}
	return QSqlQueryModel::headerData(section, orientation, role);
}

---

Can somebody help me with this??