Does 'QSqlQueryModel' have a bug?

[nuntawat]

Hello. Now I have a problem when using QSqlQueryModel or QSqlTableModel. I installed an open-source version of Qt 4.6.2 for VS2008 and Qt 1.4.4 add-in for VS2008 on WinXP. The VC++ compiler always throw the error message "error C2248: 'QSqlTableModel::setQuery' : cannot access protected member declared in class 'QSqlTableModel'" when I set a parameter in setQuery() function as below:

QSqlTableModel *model;
 
// assume that 'stock' is a table.
model->setQuery(tr("SELECT * FROM stock WHERE id = %1").arg(ui.searchComboBox->currentText()));

QSqlTableModel *model;

// assume that 'stock' is a table.
model->setQuery(tr("SELECT * FROM stock WHERE id = %1").arg(ui.searchComboBox->currentText()));

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or

QSqlTableModel *model;
 
// assume that 'stock' is a table.
model->setQuery("SELECT * FROM stock WHERE id = 1");

QSqlTableModel *model;

// assume that 'stock' is a table.
model->setQuery("SELECT * FROM stock WHERE id = 1");

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But according to a Qt documentation, it said that user can pass a string into setQuery() function. So is it a bug and what should I do?

Thanks a lot!