QML, QSqlTableModel: not saving data

Bilal_Khan

Hi, my data is being displayed by rolenames successfully but "setData" is not working. This function is receiving everything right from qml but the final call to

 QSqlTableModel::setData

does not work, returns "false" & there are no errors.

QVariant ItemModel::data(const QModelIndex & index, int role) const {
    // qDebug() << role_names.value(role);
    //  QString role_str = QString(roles.value(role));
    qDebug() << index.row();
    QModelIndex modelIndex = this->index(index.row(), role - Qt::UserRole - 1 );
    return  QSqlQueryModel::data(modelIndex, Qt::DisplayRole);
}

bool ItemModel::setData(const QModelIndex &index, const QVariant &value, int role) {
    qDebug() << role_names.value(role) << " " << value << " " << index.row() << " " << index.column() << " " << role - Qt::UserRole - 1;
    QModelIndex modelIndex = this->index(index.row(), role - Qt::UserRole - 1);
  //  this->query().seek(index.row());
  //  qDebug() << this->query().record().value(1);

    qDebug() << QSqlTableModel::setData(modelIndex,value);
    qDebug() << lastError();
    emit dataChanged(modelIndex,modelIndex);
    return true;
}

void ItemModel::generateRoleNames()  {
    this->role_names.clear();
    for (int i = 0; i < record().count(); ++i)   {
        role_names[Qt::UserRole + i + 1] = record().fieldName(i).toUtf8();
    }
}

I have experience with abstract models but SQL models are giving me hardtime. I have no idea why it is not working. Any help will be much appreciated.

SGaist

Hi,

@Bilal_Khan said in QML, QSqlTableModel: not saving data:

modelIndex

Are you sure this index is valid ?

Bilal_Khan

This modelIndex is computed in both functions (data() & setData()) in the same way but it does not work while setting data. I have also tried this->index with different literal values but no success so far..

itemModel->setEditStrategy(QSqlTableModel::OnFieldChange);

Bilal_Khan

Update (UBUNTU 20.04/ Qt-5.13 & 6.12/ SQLITE3 & PSQL):

I no longer override setData and directly call the parent's implementation:

qDebug() <<  itemModel->setData(itemModel->index(0, 1), "NEW VALUE", Qt::EditRole); // false
 qDebug() << itemModel->lastError();   // QSqlError("", "", "")

but no vain.

Surprisingly, there are no errors on passing invalid index.
I confirm that setRecord is also not working (no errors)

 ItemModel *itemModel = new ItemModel(nullptr,db);
 itemModel->setEditStrategy(QSqlTableModel::OnFieldChange);
 itemModel->setTable("items");
 itemModel->generateRoleNames();
 itemModel->select();
 qDebug() <<  itemModel->rowCount(); // 2
 itemModel->query().seek(0);
 QSqlRecord rec = itemModel->query().record();

 rec.setValue(1, QString("SOMETHING"));
 qDebug() << itemModel->setRecord(0,rec);  //true

 QModelIndex index = itemModel->index(0, 0);
 qDebug() << "Update" << itemModel->data(index, 258);   // old value returned

Bilal_Khan

It's just the problem with subclassing. setData does not work.

  enum ItemRoles {
        CONTENTROLE = Qt::UserRole + 1,
        TYPEROLE = Qt::UserRole + 2,
        VIEWSROLE = Qt::UserRole + 3,
        WEIGHTROLE
    };
QHash<int, QByteArray> ItemModel::roleNames() const  {
       QHash<int, QByteArray> roles;
       roles[CONTENTROLE] = "content";
       roles[TYPEROLE] = "type";
       roles[VIEWSROLE] = "views";
       roles[WEIGHTROLE] = "weight";
       return roles;
}
bool ItemModel::setData(const QModelIndex &index, const QVariant &value, int role) {
    QModelIndex modelIndex = this->index(index.row(), role - Qt::UserRole);

    qDebug() << QSqlTableModel::setData(modelIndex,value, Qt::EditRole); // true
    qDebug() << lastError();
    emit dataChanged(modelIndex,modelIndex);
    return true;
}

//
QModelIndex index = itemModel->index(0, 0);
itemModel->setData(index, "VALUE",  itemModel->CONTENTROLE);
 qDebug() <<  itemModel->data(index, itemModel->CONTENTROLE); // unchanged data

SGaist

What if you call submit after setRecord ?

Bilal_Khan

Yes, I did but does not work

SGaist

Can you provide a minimal compilable example so that it's possible to reproduce your issue.

Bilal_Khan

Hi,
Thank you @SGaist for your kind support ... so far

As you could see , I have made some changes. Now, after the update in setData, the data function returns qvariant(invalid).

Project Link:
Test Qt Project

Bilal_Khan

@SGaist , sorry to bother you again. Did you check it, what you have found?

SGaist

This works correctly.

#ifndef ITEMMODEL_H
#define ITEMMODEL_H

#include <QSqlTableModel>

class ItemModel : public QSqlTableModel {
    Q_OBJECT
public:

    enum ItemRoles {
        IDROLE = Qt::UserRole + 1,
        CONTENTROLE = Qt::UserRole + 2,
        TYPEROLE = Qt::UserRole + 3,
        VIEWSROLE = Qt::UserRole + 4,
        WEIGHTROLE
    };
    Q_ENUMS(ItemRoles)

    ItemModel(QObject *parent = nullptr, QSqlDatabase db = QSqlDatabase());

    QVariant data(const QModelIndex & index, int role = Qt::DisplayRole) const;
    bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole);

    QHash<int, QByteArray> roleNames() const;

private:
    Q_DISABLE_COPY(ItemModel);

    QModelIndex indexForRole(const QModelIndex& index, int role) const;
};

#endif // ITEMMODEL_H

#include "ItemModel.h"

ItemModel::ItemModel(QObject *parent, QSqlDatabase db):
    QSqlTableModel(parent, db)
{

}

QVariant ItemModel::data(const QModelIndex & index, int role) const
{
    return QSqlTableModel::data(indexForRole(index, role), Qt::EditRole);
}


bool ItemModel::setData(const QModelIndex &index, const QVariant &value, int role)
{
    return QSqlTableModel::setData(indexForRole(index, role), value, Qt::EditRole);
}


QHash<int, QByteArray> ItemModel::roleNames() const  {
       QHash<int, QByteArray> roles;
       roles[IDROLE] = "id";
       roles[CONTENTROLE] = "content";
       roles[TYPEROLE] = "type";
       roles[VIEWSROLE] = "views";
       roles[WEIGHTROLE] = "weight";
       return roles;
}


QModelIndex ItemModel::indexForRole(const QModelIndex& index, int role) const
{
    int row = index.row();
    int column = index.column();
    if (role > Qt::UserRole) {
        column = role - Qt::UserRole - 1;
    }
    return this->index(row, column);
}