Query Model Example

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#include <QtSql>

#include "editablesqlmodel.h"

EditableSqlModel::EditableSqlModel(QObject *parent)
    : QSqlQueryModel(parent)
{
}

Qt::ItemFlags EditableSqlModel::flags(
        const QModelIndex &index) const
{
    Qt::ItemFlags flags = QSqlQueryModel::flags(index);
    if (index.column() == 1 || index.column() == 2)
        flags |= Qt::ItemIsEditable;
    return flags;
}

bool EditableSqlModel::setData(const QModelIndex &index, const QVariant &value, int /* role */)
{
    if (index.column() < 1 || index.column() > 2)
        return false;

    QModelIndex primaryKeyIndex = QSqlQueryModel::index(index.row(), 0);
    int id = data(primaryKeyIndex).toInt();

    clear();

    bool ok;
    if (index.column() == 1) {
        ok = setFirstName(id, value.toString());
    } else {
        ok = setLastName(id, value.toString());
    }
    refresh();
    return ok;
}

void EditableSqlModel::refresh()
{
    setQuery("select * from person");
    setHeaderData(0, Qt::Horizontal, QObject::tr("ID"));
    setHeaderData(1, Qt::Horizontal, QObject::tr("First name"));
    setHeaderData(2, Qt::Horizontal, QObject::tr("Last name"));
}

bool EditableSqlModel::setFirstName(int personId, const QString &firstName)
{
    QSqlQuery query;
    query.prepare("update person set firstname = ? where id = ?");
    query.addBindValue(firstName);
    query.addBindValue(personId);
    return query.exec();
}

bool EditableSqlModel::setLastName(int personId, const QString &lastName)
{
    QSqlQuery query;
    query.prepare("update person set lastname = ? where id = ?");
    query.addBindValue(lastName);
    query.addBindValue(personId);
    return query.exec();
}