Problem with Key

nanndoj · **Joined:** Tue Aug 14, 2007 11:47 am **Posts:** 6

Hi,

I'm new in this forum and start using Hibernate recently. I will try to detail my problem the best I can.

First: I have two persistent classes: Page and Category.
Second: Into Page class contains one instance of Category class. See example below.

Code:

   
public class Page {
     private int code;
     private String name;
     private Category category;
 
    // Getters and setters methods
    ....
  }

  public class Category {
    private int code;
    private String name;
  }

Third: In my database the tables are mapped. Its are working correctly.

This is my context. My problem is when the Page is stored. The table mapped by the Category class are populated with data.

When I try to insert a Page, a key violation happens in Category Class. How I can store a Page using a Category which already exists in database?. Example

Code:

Category cat = new Category();
cat.setCode(500) // Code 500 already exist in database

Page page = new Page();
page.setName("Test Page");
page.setCategory(cat);

HibernateUtil.store(page) //Violation of key here

How can I do it ??
tanks

thatmikewilliams · **Posted:** Thu Aug 16, 2007 4:30 am

You need to post your mapping files for these classes.

nanndoj · **Joined:** Tue Aug 14, 2007 11:47 am **Posts:** 6

Okay,
This is the code of my PageDTO class.

Code:

@Entity
@Table(name = "page")
@Inheritance(strategy = InheritanceType.JOINED)
public abstract class PageDTO extends DTO {

  private CategoryDTO           category;
  private Date                        dateCreation;
  private Integer                    height;
  private String                      name;


  // Constructor
  public PageDTO() {
  }

  // Methods
  @OneToMany(mappedBy = "parent")
  public List<PageDTO> getChildren() {
    return this.children;
  }

  @OneToOne(cascade = CascadeType.ALL)
  @JoinColumn(name = "category_id")
  public CategoryDTO getCategory() {
    return this.category;
  }

  @Temporal(TemporalType.DATE)
  @Column(name = "pag_date_creation", nullable = false)
  public Date getDateCreation() {
    return this.dateCreation;
  }

  @Basic
  @Column(name = "pag_height", nullable = false)
  public Integer getHeight() {
    return this.height;
  }

  @Basic
  @Column(name = "pag_name", nullable = false, length = 50)
  public String getName() {
    return this.name;
  }

  public void setCategory(CategoryDTO category) {
    this.category = category;
  }

  public void setDateCreation(Date dateCreation) {
    this.dateCreation = dateCreation;
  }

  public void setHeight(Integer height) {
    this.height = height;
  }

  public void setName(String name) {
    this.name = name;
  }

}

Now. This is the code of CategoryDTO class

Code:

@Entity
@Table(name="category")
public class CategoryDTO extends DTO {

  // Atributos da Classe
  private static final long serialVersionUID = -776137723692955756L;
  private String            description;
  
  // Construtors
  public CategoryDTO() {
    
  }
  
  public CategoryDTO(String description) {
    this.setDescription(description);
  }
  
  //Métodos
  @Basic
  @Column(name="cat_description", nullable = false, length = 50)
  public String getDescription() {
    return this.description;
  }

  public void setDescription(String description) {
    this.description = description;
  }
}

DTO class contains the attribute named code;

I want insert two pages in same category!!
page1 -> category1
page2 -> category1 // Key violation here!!

example:

Code:

CategoryDTO cat = new CategoryDTO("test")
cat.setCode(1);

PageDTO p1 = new PageDTO();
pageDTO p2 = new PageDTO();

p1.setCategory(cat);
p2.setCategory(cat);

HibernateUtil.store(p1); // Work
HibernateUtil.store(p2); // Key violation in category

Tanks!!

thatmikewilliams · **Posted:** Sat Aug 18, 2007 4:28 am

You've mapped category as OneToOne in Page but you're trying to link 2 pages to one category. Page->Category should therefor be ManyToOne.