HiberNate过滤器不适用于加入实体

Question

我试图理解Hibernate过滤器，我认为即使查询不是从过滤的实体开始，也可以应用过滤器，如果我只是加入它。

我的实体：

@Table(name = "SPM_SECTION", schema = "TEST")
@GenericGenerator(name = "MODSEC_ID.GEN", strategy = "uuid2")
public class ModuleSection implements Serializable {

private AcademicClass academicClass;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "CLASS_ID")
    public AcademicClass getAcademicClass() {
        return academicClass;
    }

    public void setAcademicClass(AcademicClass academicClass) {
        this.academicClass = academicClass;
    }
    
}

@Entity
@GenericGenerator(name = "AC_CLASS_ID.GEN", strategy = "uuid2")
@Where(clause="1=1")
@FilterDef(name= Resources.SECURITY_FILTER_NAME, parameters={@ParamDef(name=Resources.SECURITY_FILTER_PARAMETER, type="string")})
@Filter(name=Resources.SECURITY_FILTER_NAME, condition = "DISCRIMINATOR_ID in (:"+Resources.SECURITY_FILTER_PARAMETER+")")
@Table(name = "ACADEMIC_CLASS", schema = "TEST", uniqueConstraints = @UniqueConstraint(columnNames = {"OUS_ID", "YEAR_ID",
        "PERIOD_ID", "SHIFT_ID", "SEMESTER", "CODE" }))
public class AcademicClass implements java.io.Serializable {

    //I tried by having the association here, i also tried without it.
    private Set<ModuleSection> sections = new HashSet<>(0);
    
    @OneToMany(fetch = FetchType.LAZY, mappedBy = "academicClass")
    public Set<ModuleSection> getSections() {
        return this.sections;
    }

    public void setSections(Set<ModuleSection> sections) {
        this.sections = sections;
    }

}

过滤器通过拦截器启用，为了安全起见，从数据库中获取参数列表。

当我执行这样的查询时：

em.createQuery("select acc from AcademicClass acc ...........", AcademicClass.class)
.getResultList();

过滤器被应用了。但是我也希望当我的查询从模块部分开始时应用过滤器：

em.createQuery("select ms from ModuleSection ms join ms.academicClass acc", AcademicClass.class)
.getResultList();

在上述查询中，没有应用筛选器。

ModuleSect实体中的学术类为null，但我也有其他实体不为空，其中上述情况不起作用。

我还试图在模块节中应用@Filter或@FilterJoinTable属性，但没有运气：

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "CLASS_ID")
    @Filter(name=Resources.SECURITY_FILTER_NAME, condition = "DISCRIMINATOR_ID in (:"+Resources.SECURITY_FILTER_PARAMETER+")")
    @FilterJoinTable(name=Resources.SECURITY_FILTER_NAME, condition = "DISCRIMINATOR_ID in (:"+Resources.SECURITY_FILTER_PARAMETER+")")
    public AcademicClass getAcademicClass() {
        return academicClass;
    }

我的问题：过滤器是否意味着只过滤from子句中的实体？过滤器是否适用于连接实体？如果我想实现上述内容，我是否也应该在ModuleSect中添加一个DISCRIMINATOR_ID，并从那里开始将过滤器添加到该实体？

Answer 1

hibernate文档中对此保持沉默，但似乎这是真的，@Filter只应用于from子句。

假设我们有以下映射：

@Entity
@Table(name = "ACADEMIC_CLASS")
@FilterDef(
   name="isAccessible",
   parameters = @ParamDef(
      name="sec",
      type="string"
   )
)
@Filter(
   name="isAccessible",
   condition="{acClass}.discriminator_id in (:sec)",
   aliases = {
      @SqlFragmentAlias(alias = "acClass", table= "TEST_SCHEMA.ACADEMIC_CLASS")
   }
)
public class AcademicClass
{
   @Id
   @Column(name = "class_id")
   private Long id;

   @OneToMany(fetch = FetchType.LAZY, mappedBy = "academicClass")
   private Set<ModuleSection> sections;

   // getters/setters
}

@Entity
@Table(name = "SPM_SECTION")
public class ModuleSection
{
   @Id
   @Column(name = "sec_id")
   private Long id;

   @ManyToOne(fetch = FetchType.LAZY)
   @JoinColumn(name = "sec_class_id")
   private AcademicClass academicClass;

   // getters/setters
}

当我们运行以下查询时：

session
   .enableFilter("isAccessible")
   .setParameter("sec", "A1");

List<AcademicClass> classes = session.createQuery(
    "select ac from ModuleSection ms join ms.academicClass ac",
    AcademicClass.class
).getResultList();

没有应用过滤器。它应该发生在JoinSequence.toJoinFrach中。在这种情况下，filterCon条件是空的。

但对于以以下方式重写的查询：

List<AcademicClass> classes = session.createQuery(
    "select ac from ModuleSection ms, AcademicClass ac where ms.academicClass = ac",
    AcademicClass.class
).getResultList();

我们将有：

结果将生成以下查询：

Hibernate: 
/* select
     ac 
   from
      ModuleSection ms,
      AcademicClass ac 
   where
        ms.academicClass = ac
*/
select
   academiccl1_.class_id as class_id1_0_ 
from TEST_SCHEMA.SPM_SECTION modulesect0_ cross 
join TEST_SCHEMA.ACADEMIC_CLASS academiccl1_ 
where academiccl1_.discriminator_id in (?) 
  and modulesect0_.sec_class_id=academiccl1_.class_id

因此，作为一种解决方法，您可以用这种方式重写查询。

只有在父实体和子表之间有链接表的情况下，才能使用@FilterJoinTable注释。