modify jdbc.update
finish unpdateCategory method in controller
delete useless codes
finish can_insert_item test
finish insertItem in service
add insertItem method in dao
finish insertItem in service
rename insertItem to insertCategory
rename insertItem to insertCategory
add margin
add default constructor
delete final tag
finish can_update_item_by_id test
add updateItemById method in dao
add updateItemById method in service
finish updateItemById method in service
finish updateItemById in dao
finish updateItemById in controller
add id to PUT Url
create CartItemServiceImplTest class