-----MainWindow.cpp------

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
connect(ui.showBtn, &QPushButton::clicked, this, &MainWindow::init);
}


void MainWindow::init() {
    bool ok;
    QString text = QInputDialog::getText(this, tr("QInputDialog::getText()"),
        tr("Podaj haslo do bazy:"), QLineEdit::Normal,
        QDir::home().dirName(), &ok);


    mydb = QSqlDatabase::addDatabase("QSQLCIPHER");
    mydb.setDatabaseName("TotallyNotDBWithPasswords.db");
    mydb.setPassword(text);
    mydb.setConnectOptions("QSQLITE_USE_CIPHER=sqlcipher");
    mydb.open();

    table_model = new QSqlTableModel(this, mydb);

    table_model->setTable("Account");
    table_model->setHeaderData(0, Qt::Horizontal, QObject::tr("nr"));
    table_model->setHeaderData(1, Qt::Horizontal, QObject::tr("strona"));
    table_model->setHeaderData(2, Qt::Horizontal, QObject::tr("haslo"));
    table_model->select();

    ui.tableView->setModel(table_model);
}


-----MainWindow.h------

class MainWindow : public QMainWindow
{
    Q_OBJECT
private:
    QSqlTableModel *table_model;
    QSqlDatabase mydb;
public:
    void init();
};