Change cell data in tableview QT

hubeytqew

I am trying to pull data's in database then print on tableview then change them one by one. I can reach each of the cells (in later times I'll iterate it via for whatever..) but I can't change them. This is the code when I press the button, it shows database data's without a problem but I can't change them. How can I achieve this?

void manager::on_pushButton_show_clicked()                      
{
    connOpen();
    QSqlQueryModel * modal = new QSqlQueryModel();
    QSqlQuery* qry = new QSqlQuery(mydb);
    qry->prepare("select * from data");
    qry->exec();
    modal->setQuery(*qry);
    ui->tableView->setModel(modal);      //up to now, there is no problem, table appears as expected..
    QString cellstring = ui->tableView->model()->data(ui->tableView->model()->index(0,2)).toString();
    qDebug() << cellstring;              //I can read the cell's data, *cellstring* holding it
    QString newstring = "hello";
*1  ui->tableView->model()->setData(ui->tableView->model()->index(0,2), newstring);
*2  QString another = ui->tableView->model()->data(ui->tableView->model()->index(0,2)).toString();
    qDebug() << another;

in number1 line I try to change the data inside the cell.
in number2 line I read the cell's data then print it, but there is no change at all.
I still see the old variable;

It prints: abcdefgh
It should print: hello

Is the setData method does not work properly? Any suggestions? Thanks.
I am newbie here, I wish I clearly express myself..

Bonnie

From the document of QSqlQueryModel:

The model is read-only by default. To make it read-write, you must subclass it and reimplement setData() and flags(). Another option is to use QSqlTableModel, which provides a read-write model based on a single database table.

hubeytqew

@Bonnie Is there an example for this? I did not implement subclass. Thx.

Edit: I want to fetch database then do some calculations on it then print it via table. If I use QSqlTableModel original database variables will change? It should not be change.

Edit2: Yes it was. I changed the table in the app, and there is no changing in database. Thx Bonnie..

hubeytqew

This post is deleted!

Bonnie

@hubeytqew Well, actually it can change the database, and the behaviour is depending on the QSqlTableModel::editStrategy().
If you don't want original database changed, make sure to set the edit strategy to QSqlTableModel::OnManualSubmit.
Then it will only try to modify the database when you call QSqlTableModel::submitAll().
You really need to look through the documents before asking questions :)