I will put it in a simpler way. Consider a straight table.
Table : contains products for which operations were performed on a day.
The Nprinting reports will print report for these three materials.
If there were no operations performed on a particular day for any of these products, the table will be empty.
In that case, the report has to carry the information “No materials operated" or any hardcoded text.
But when the table is empty, the Nprinting throws an exception error " Void constructor error.......Sequence contains no elements"