QTableWidget and SQL (dynamic) not working

[cxam]

Hi!
In my program I have a QTableWidget that shows information queried, this is the code:

   int i = 0;
    while (query.next()) {
        //Establecemos un QTableWidget por cada columna
        ui->tableWidget->setItem(i,0,new QTableWidgetItem(query.value(0).toString()));
        ui->tableWidget->setItem(i,1,new QTableWidgetItem(query.value(1).toString()));
        ui->tableWidget->setItem(i,2,new QTableWidgetItem(query.value(2).toString()));
        ui->tableWidget->setItem(i,3,new QTableWidgetItem(query.value(3).toString()));
        ui->tableWidget->setItem(i,4,new QTableWidgetItem(query.value(4).toString()));
        ui->tableWidget->setItem(i,5,new QTableWidgetItem(query.value(5).toString()));
        ui->tableWidget->setItem(i,6,new QTableWidgetItem(query.value(6).toString()));
        ui->tableWidget->setItem(i,7,new QTableWidgetItem(query.value(7).toString()));
        i++;
        recCount++;
    }

Unfortunately it only shows 1 result even though the query is correct.

"i" is the number of the row and "recCount" doesn't has anything to do with the table.

Thanks in advance

[SGaist]

Hi,

You don't add any row to your QTableWidget or did you do before running that loop ?

Also, why not use a QTableView with QSqlQueryModel ?

[cxam]

@SGaist "i" is the number of rows that add's +1 at the end of the loop

[cxam]

@SGaist But how QtableView works ?

[Joel Bodenmann]

I can recommend reading these two articles to not only understand the model/view concept but also how Qt implements it:

• https://doc.qt.io/qt-5/model-view-programming.html
• https://doc.qt.io/qt-5/modelview.html

As @SGaist pointed out there's an existing model that allows you to display SQL query results in a QTableView. The model is called QSqlQueryModel. You'd basically use a QTableView instead of a QTableWidget and use QTableView::setModel() to set the QSqlQueryModel as the model for the table view.

[cxam]

@Joel-Bodenmann I tried to use QTableView but actually it would break a lot of my code so unless it's completely necessary I won't use it. I'm focusing on trying to solve my current issue.

[SGaist]

What would break ?

In any case, I don't see you creating new rows. The incrementation of i doesn't mean your QTableWidget will have an additional row unless you did it before your while loop.

[Joel Bodenmann]

@cxam QTableWidget actually inherits from QTableView so it shouldn't break anything in terms of the GUI. In terms of the data handling: You just outsource that to the model. As there's an existing model that is designed specifically for handling SQL queries I can imagine that the only thing it would do is drastically simplify your life.
The QTableWidget really is just a QTableView with an internal model. That model is a generic model. Using the QTableView would allow you to use the SQL query specific QSqlQueryModel.

@SGaist QTableWidget::setItem() actually creates the row internally.

[cxam]

@Joel-Bodenmann Hmm I see. I'll check it out then, thanks for your help.

[SGaist]

@Joel-Bodenmann No it doesn't. First thing done, it checks whether the row, column combination returns a valid index if not then it returns immediately.

[Joel Bodenmann]

@SGaist Yes, you are correct. I am sorry for giving wrong information.

@cxam So as @SGaist pointed out in his first post: Make sure that your QTableWidget "has enough rows".
But anyway, I'd still recommend going with QTableView and QSqlQueryModel in your case.

[cxam]

@SGaist Indeed, you're right When I set the properties for my table I set that the number of rows was "1" so I have to create an "int" variable and then say that the number of rows is that variable starting from 1 and then increment that number on the loop.