code: public BigDecimal getInternalBigDecimal(ColumnInformation columnInfo) {
      if (lastValueWasNull()) {
        return null;
      }
  
      if (columnInfo.getColumnType() == ColumnType.BIT) {
        return BigDecimal.valueOf(parseBit());
      }
      return new BigDecimal(new String(buf, pos, length, StandardCharsets.UTF_8));
    }
docs: Get BigDecimal from raw text format.
  
  @param columnInfo column information
  @return BigDecimal value