在java中使用@Filter hibernate注释过滤集合 [英] Filtering a collection using the @Filter hibernate annotation in java

问题描述

有2个实体B集合，我想根据B中的属性过滤每个集合（如下面的代码所示）。

  @FilterDefs（）
 class A {
 
 @OneToMany（mappedBy =productType，fetch = FetchType.LAZY，cascade = CascadeType.ALL）
 @Filter（name =something，condition =entityType ='SKU1'）
 Set< ; B个set1 = new HashSet< B>（）; 
 
 @OneToMany（mappedBy =productType，fetch = FetchType.LAZY，cascade = CascadeType.ALL）
 @Filter（name =something，condition =entityType ='SKU2' ）
设置< B> set2 = new HashSet< B>（）; 
 
 
 
 class B {
 
 @ManyToOne（cascade = CascadeType.ALL）
 private productType; 
 
 @Column（name =entity_type）
 @Enumerated（EnumType.STRING）
 private EntityType entityType; 
} 
  

编辑：
我按照以下建议启用过滤器DAO方法。但是，我收到以下异常：
$ b

org.hibernate.exception.SQLGrammarException：无法初始化
集合

>

如果我使用急切的加载方法，我得到一个异常来处理生成的无效SQL？

任何指针？

解决方案

我在实体中使用FilterDef，然后设置我想要使用的极其集合过滤器。在你的例子中：

  class A {
 @OneToMany（...）
 @Filter（name =filterName）
设置< B> set2 = new HashSet< B>（）; 
 
 $ b $ @FilterDef（name =filterName，
 defaultCondition = condition，
 parameters = {@ParamDef（name = nameParameter，
 type =然后，正如ssedano所说的那样，你可以通过使用它来创建一个新的数据库，应在会话中启用过滤器：
  session.enableFilter（filterName）
  
 
 
如果是这种情况，请输入参数：
 
 
  session.getEnabledFilter（FILTERNAME）.setParameter（nameParameter，值）; 
  
 
I have two hibernate mapped entities A and B.  

A has 2 collections of entity B and I would like to filter each collection based on a property held in B (as shown in code below).
@FilterDefs()
class A{

@OneToMany(mappedBy = "productType", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@Filter(name = "something", condition = "entityType = 'SKU1'")  
Set<B> set1 = new HashSet<B>();

@OneToMany(mappedBy = "productType", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@Filter(name = "something", condition = "entityType = 'SKU2'")  
Set<B> set2 = new HashSet<B>();

 }

class B{

@ManyToOne(cascade = CascadeType.ALL)
private A productType;

@Column(name = "entity_type")
@Enumerated(EnumType.STRING)
private EntityType entityType;
}
Edited:
I am enabling the filters as suggested below in my DAO method.  However, I am getting the following exception

  
org.hibernate.exception.SQLGrammarException: could not initialize a
  collection
If i use the eager loading method, I am getting an exception to do with invalid SQL getting generated?

Any pointers?
解决方案
I use FilterDef in the Entity and then set in wich collections I want to use the filter. In your example:
class A{
@OneToMany(...)
@Filter(name = "filterName")  
Set<B> set2 = new HashSet<B>();
}

@FilterDef(name = "filterName", 
    defaultCondition = condition,
    parameters = {@ParamDef(name = nameParameter,
    type = typeParameter)})
class B{
}
Then as ssedano said you should enable filter in the session: 
session.enableFilter("filterName")
And put the params if it is the case:
session.getEnabledFilter(filterName).setParameter(nameParameter,value);


                        
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