Method read

src/frontend/datasources/ImportSQLDatabaseWidget.cpp:418–518

}

void ImportSQLDatabaseWidget::read(AbstractDataSource* dataSource, AbstractFileFilter::ImportMode importMode) {
	if (!dataSource)
		return;

	// execute the current query and determine the start/end rows and columns to read
	QSqlQuery q;
	if (!prepareAndExecute(q) || m_actualRows == 0) {
		RESET_CURSOR;
		return;
	}

	// pointers to the actual data containers
	// columnOffset indexes the "start column" in the datasource. Data will be imported starting from this column.
	std::vector<void*> dataContainer;
	bool ok = false;
	const int columnOffset = dataSource->prepareImport(dataContainer, importMode, m_actualRows, m_actualCols, m_actualColumnNames, m_actualColumnModes, ok);
	// TODO: error handling
	if (!ok)
		return;

	// number and DateTime formatting
	const auto& dateTimeFormat = ui.cbDateTimeFormat->currentText();

	// TODO: use general setting for decimal separator?
	QLocale::Language lang;
	if (ui.cbDecimalSeparator->currentIndex() == 0)
		lang = QLocale::Language::C;
	else
		lang = QLocale::Language::German;
	const QLocale numberFormat = QLocale(lang);

	// read the data
	int progressIndex = 0;
	const qreal progressInterval = 0.01 * m_actualRows; // update on every 1% only
	int rowIndex = 0;
	while (q.next()) {
		if (rowIndex < m_startRow) {
			++rowIndex;
			continue;
		}

		if (rowIndex > m_endRow)
			break;

		for (int colIndex = m_startCol; colIndex <= m_endCol; ++colIndex) {
			const auto& valueString = q.value(colIndex).toString();
			const int col = colIndex - m_startCol;
			const int row = rowIndex - m_startRow;

			// set the value depending on the data type
			switch (m_actualColumnModes.at(col)) {
			case AbstractColumn::ColumnMode::Double: {
				bool isNumber;
				const double value = numberFormat.toDouble(valueString, &isNumber);
				static_cast<QVector<double>*>(dataContainer[col])->operator[](row) = (isNumber ? value : NAN);
				break;
			}
			case AbstractColumn::ColumnMode::Integer: {