Data is Null. This method or property cannot be called on Null values

Question

I\'m working on an application where one can get information on movies from a database as well as add, update and delete the movies. In the database I have three tables (Movie,

Answer 1

BookingQuantity - column having null value in DB. but actual DB BookingQuantity not null column. Some rare case it happens to enter. In that case below code throw error the same error(Data is Null. This method or property cannot be called on Null values ).

totalBookingQuantity += item.InspPoTransactions.Where(x => x.PoId == inspectionPODetail.PoId && x.ProductId == inspectionPODetail.ProductId).Sum(x => Convert.ToInt32(x.BookingQuantity));