Unable to define/override @Id(s) on a subclass; which classes i have to solve?

[Thanaphorn Thongthien]

i got this error


Caused by: org.hibernate.AnnotationException: Unable to define/override @Id(s) on a subclass: MPrint.MVC.Model.Paper

and these are my codes

@Entity
public class Paper extends PaperSize{

	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	Long id;
	@Column(unique = true)
	private String paperNo;
	@Column
	private String paperName;
	@Column
	private String paperType;
	@Column
	private String paperTypeRemark;
	@Column
	private String paperSizeNo;
	@Column
	private String paperSizeRemark;
	@Column
	private int gram;
	@Column
	private double paperPrice;
	@Column
	private String paperShop;
	@Column
	private String paperRemark;

	public Paper() {

	}

	public Paper(String paperNo, String paperName, String paperType,
			String paperTypeRemark, PaperSize paperSizeNo,
			PaperSize paperSizeRemark, int gram, double paperPrice,
			String paperShop, String paperRemark) {
		super();
		paperNo = paperNo;
		paperName = paperName;
		paperType = paperType;
		paperTypeRemark = paperTypeRemark;
		paperSizeNo = paperSizeNo;
		paperSizeRemark = paperSizeRemark;
		gram = gram;
		paperPrice = paperPrice;
		paperShop = paperShop;
		paperRemark = paperRemark;
	}

PaperSize

   @Entity
//@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public class PaperSize {
	@Id
	@GeneratedValue(strategy = GenerationType.AUTO)
	Long id;
	@Column
	private String paperSizeNo;
	@Column
	private double paperWidth;
	@Column
	private double paperLength;
	@Column
	private String paperUnit;

	public PaperSize() {

	}

	public PaperSize(String paperSizeNo, double paperWidth, double paperLength,
			String paperUnit) {
		super();
		paperSizeNo = paperSizeNo;
		paperWidth = paperWidth;
		paperLength = paperLength;
		paperUnit = paperUnit;
	} 

i just need the table Paper keep the data only PaperSizeNo

but the details of PaperSizeNo will keep in their table that have width, length and unit ( inch, cm)

for easy to manage the database,, another class of my project were create relation diagram like these problem classes

how can i solve it,, really need help ! (T - T)

in the early, i have already added the single class to DB and it's work!

what about the parent and child class?? i don't know where to adapt them..

ps. i'm quite new with these,, [first programming] - -'

[Wendy Gibbons]

Thanaporn Thongthien wrote:

i just need the table Paper keep the data only PaperSizeNo

but the details of PaperSizeNo will keep in their table that have width, length and unit ( inch, cm)

for easy to manage the database,, another class of my project were create relation diagram like these problem classes

I am really sorry i tried helping you but i found some of the english really difficult to understand (quoted above) could you supply us with the database design indicating the foreign keys and another go at the quoted sentances.

[Thanaphorn Thongthien]

thanks for reply anyway and this is the database column that i will keep in PAPER and PAPERSIZE

Paper's Database will keep

PaperNo
PaperName
PaperType
PaperSizeNo
PaperGram
PaperPrice

PaperSize's Database

PaperSizeNo
PaperWidth
PaperLenght
PaperUnit

that is what i mean - - '

[Wendy Gibbons]

ok, i am not sure if you are using annotations or xml files but look into the many-to-one annotation for the paperSizeNo column
and pay special attention to cascade.