使用Hibernate Criteria在不同列上连接三个实体所需的帮助

Question

更新了问题

我有3张表，比如

Section (id, title, url)//id is Primary key
Category (id, title)//id is Primary key
SubCategory (id, title)//id is Primary key

在这里，我想像

这样的简单查询加入这些表

Select * From Category cat, Section se, SubCategory subCat  WHERE
 subCat.id=23456  AND subCat.category=cat.id  AND subCat.section = se.id

如何在Hibernate中使用Criteria实现上述查询？能够 有人帮我这个吗？

在此处添加我的问题

我的实体文件如下：

@Entity
@Table(name="section")
public class SectionEntity{
  private int id;
  private String title;
  //Getter & setter method
}

---

@Entity
@Table(name="category")
public class CategoryEntity{
  private int id;
  private String title;
  private Set<SubCategoryEntity> subCategory;
  //Getter & setter method
  @OneToMany(cascade = CascadeType.ALL, fetch=FetchType.LAZY)
  @JoinColumn(name="category", insertable=false, updatable=false)
  public Set<SubCategoryEntity> getSubCategory(){
    return this.subCategory;
  }
}

---

更新了SubCategoryEntity

@Entity
@Table(name="subcategory")
public class SubCategoryEntity{
  private int id;
  private String title;

  private Set<SectionEntity> sectionEntity;

  //Getter & setter method
  @OneToMany(fetch=FetchType.LAZY)
  @JoinColumn(name="id", insertable=false, updatable=false)
  public Set<SectionEntity> getSectionEntity(){
    this.section;
  }
}

---

使用Hibernate Criteria的步骤：

  

第1步：为类别实体创建条件           Criteria categoriesCriteria = session.createCriteria（CategoriesEntity.class，“categoryEntity”）;

     

步骤2：创建SubCategoryEntity和SectionEntity的别名           categoriesCriteria.createAlias（“categoryEntity.subCategoryEntity”，“subCatEntity”）;           categoriesCriteria.createAlias（“subCatEntity.sectionsEntity”，“subCatSectionEntity”）;

     

步骤3：在投影列表中设置属性

     

步骤4：添加限制为：           categoriesCriteria.add（Restrictions.eq（“subCatEntity.id”，primCategoryId））;

     

步骤5：将投影属性设置为CategoryEntity Criteria           categoriesCriteria.setProjection（projPropList）;

     

第6步：获得结果           categoriesCriteria.list（）;

我的结果查询显示为：

select this_.id as y0_, this_.title as y1_, this_.sef_url as y2_, subcatenti1_.id as y3_, subcatenti1_.title as y4_, subcatenti1_.sef_url as y5_
from jos_categories this_
inner join jos_subcategories subcatenti1_ on this_.id=subcatenti1_.category
inner join jos_sections subcatsect2_ on subcatenti1_.id=subcatsect2_.id
where subcatenti1_.id=?

但我要求预期的查询为：

select this_.id as y0_, this_.title as y1_, this_.sef_url as y2_, subcatenti1_.id as y3_, subcatenti1_.title as y4_, subcatenti1_.sef_url as y5_
from jos_categories this_
inner join jos_subcategories subcatenti1_ on this_.id=subcatenti1_.category
inner join jos_sections subcatsect2_ on subcatenti1_.section=subcatsect2_.id
where subcatenti1_.id=?

我如何实现这一目标，有人可以帮助我吗？

Answer 1

在你的SubCategoryFile中进行这样的改变，

1）删除＆＃34; private int section;＆＃34;以及所有的getter和setter方法。

2）并使用此

       @JoinColumn(name="section", insertable=false, updatable=false)
       public Set<SectionEntity> getSection(){
          this.section;
           }

然后尝试运行。我希望它能起作用