@Override
    public int getInt(String columnLabel) throws SQLException {
        String stringValue = getString(columnLabel);
        if (stringValue == null || stringValue.trim().isEmpty()) {
            return 0;
        }
        try {
            return Integer.parseInt(stringValue);
        } catch (NumberFormatException e) {
            throw new SQLException("Value for column '" + columnLabel + "' is not a valid integer: " + stringValue, e);
        }
    }
Registers a transformer function for a given column.
The transformer takes the original String value and returns a new String.

@param columnLabel The name of the column (case-insensitive).
@param transformer The function that transforms the value.
jdbc-v2/src/main/java/com/clickhouse/jdbc/internal/MetadataResultSet.java