не стандартный MyTableView

QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const Q_DECL_OVERRIDE;

QVariant MyTableModel::data(const QModelIndex &index, int role = Qt::DisplayRole) const {
   QVariantValue value = QSqlQueryModel::data(index,role);
   switch(role){
   case Qt::DisplayRole:
   case Qt::EditRole:
      if(index.column()==0) return ЧтоВозвращать?
   }
}

value toXY(db, x, y) {
foreach(node in db)
if (node.x_id == x, node.y_id == y)
return node.value;
}

class XYProxy: public QAbstractProxyModel {
Q_OBJECT
  XYProxy(QObject *parent = 0) : QAbstractProxyModel(parent)   {}
  QModelIndex mapToSource(const QModelIndex &proxyIndex) const
  {
     return proxyIndex;
  }
 
  QModelIndex mapFromSource(const QModelIndex &sourceIndex) const
  {
     return sourceIndex;
  }
};
// ...

XYProxy *proxy = new XYProxy(this); //error: cannot allocate an object of abstract type ‘XYProxy’
proxy->setSourceModel(model);
view->setModel(proxy);

// http://stackoverflow.com/questions/1387912/in-qt-chaining-models-does-not-work-as-expected
class MyTableProxyModel : public QAbstractProxyModel
{
    Q_OBJECT
public:
    MyTableProxyModel (QObject* parent = 0) 
        : QAbstractProxyModel(parent) {
    }

    QModelIndex index(int row, int column, const QModelIndex& parent=QModelIndex()) const {
        return createIndex(row,column,row);
    }

    QModelIndex parent(const QModelIndex &index) const {
        //Works only for non-tree models
        return QModelIndex();
    }

    QModelIndex mapFromSource(const QModelIndex &source) const {
        return index(source.row(), source.column(), source.parent());
    }

    QModelIndex mapToSource(const QModelIndex &proxy) const {
        return (sourceModel()&&proxy.isValid())
            ? sourceModel()->index(proxy.row(), proxy.column(), proxy.parent()) 
            : QModelIndex();
    }

    QVariant data(const QModelIndex &index, int role=Qt::DisplayRole) const {
        qDebug() << "myproxymodel data";
        return mapToSource(index).data(role);
    }

    int rowCount ( const QModelIndex & parent = QModelIndex() ) const {
        return sourceModel() ? sourceModel()->rowCount(parent) : 0;
    }

    int columnCount ( const QModelIndex & parent = QModelIndex() ) const {
        return sourceModel() ? sourceModel()->columnCount(parent) : 0;
    }
};