如何使用Criteria API选择没有父Hibernate的记录？
这是我用父母选择的Java代码
getSessionFactory().getCurrentSession().createCriteria(Category.class).add(
Restrictions.eq("parent", new Category(parentId))).list();
类别Java代码
@Entity
@Table(name = "CATEGORY")
public class Category implements NamedModel{
@Id
@Column(name = "CATEGORY_ID")
@GeneratedValue(strategy = GenerationType.AUTO)
private long id;
@OneToOne(cascade = CascadeType.REMOVE, fetch = FetchType.LAZY)
@JoinTable(name = "CATEGORY_RELATIONS",
joinColumns = {
@JoinColumn(name = "CATEGORY_RELATIONS_CATEGORY_ID", referencedColumnName = "CATEGORY_ID")},
inverseJoinColumns = {
@JoinColumn(name = "CATEGORY_RELATIONS_PARENT_ID", referencedColumnName = "CATEGORY_ID")})
private Category parent;
@OneToMany(cascade = CascadeType.REMOVE, fetch = FetchType.EAGER, mappedBy = "parent")
private List<Category> children;//...
}
CategoryRelations Java代码
@Entity
@Table(name = "CATEGORY_RELATIONS")
@IdClass(CategoryRelations.CategoryRelationsPrimaryKey.class)
public class CategoryRelations implements Serializable {
@Id
@Column(name = "CATEGORY_RELATIONS_CATEGORY_ID")
private long categoryId;
@Id
@Column(name = "CATEGORY_RELATIONS_PARENT_ID")
private long parentId;
@Entity
@IdClass(CategoryRelationsPrimaryKey.class)
public static class CategoryRelationsPrimaryKey implements Serializable {
private long categoryId;
private long parentId;
}
}