[Koha] Help - Class number does not appear in items for a change in its record.

Hi, Due to some reasons, while creating biblio records, (082$a) classification number was left out (blank) and items also added with blank for class numbers. If I edit or add a new classification number in the RECORD, does not reflect for its item. Should I use: Catalog > Edit > Edit Items in Batch and add the class number for all the items manually or any other way is followed for fetching class numbers for its items from a record. With Thanks. Satish MV Librarian, Govt. Eng. College, Hassan. Karnataka. --