Sql 如何过滤JPA2中的子实体集合？

我有两个实体在一对一的关系中

@Entity
public class Employee {

@Id @GeneratedValue
public long id;

public String name;

@OneToMany
public Collection<Address> addresses = new ArrayList<Address>();
...}

@Entity
public class Address {

@Id @GeneratedValue
public long id;

public String city;
...}

这个问题是我实际问题的简化版本

我的主要问题要复杂得多，它有多个子实体，对父实体的过滤使用sql函数

由于以上原因，我无法使用HQL或本机查询

---

因此，我正在使用EntityManager、CtiteriaBuilder等工具在“仅JPA 2”中寻找解决方案。

在EclipseLink JPA中过滤关系需要使用本机API。方法是创建一个：

关于实体：

import org.eclipse.persistence.annotations.Customizer;

@Entity
@Customizer(ec.pack.z.pruebasDesarrollo.DC.class)    
public class Employee {

@Id @GeneratedValue
public long id;

public String name;

@OneToMany
public Collection<Address> addresses = new ArrayList<Address>();
...}

import org.eclipse.persistence.annotations.Customizer；
@实体
@定制器（ec.pack.z.pruebasDesarrollo.DC.class）
公营雇员{
@Id@GeneratedValue
公共长id；
公共字符串名称；
@独身癖
公共收集
3.5年后，这仍然是一个问题。但这通常应该适用于JPQL
SELECT c FROM Cat c JOIN c.kittens k WHERE k.bodyWeight>：weight
这将获取
Cat
，减少
Kitten
的收集，就像RDBMS一样。@antoniosss:No它不会。它将返回Cat实体不筛选子实体。请参阅：
package ec.pack.z.pruebasDesarrollo;

import org.eclipse.persistence.config.DescriptorCustomizer;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.expressions.Expression;
import org.eclipse.persistence.expressions.ExpressionBuilder;
import org.eclipse.persistence.mappings.OneToManyMapping;

public class DC implements DescriptorCustomizer {
 @Override
 public void customize(ClassDescriptor descriptor) throws Exception {
  OneToManyMapping oneToManyMapping = (OneToManyMapping) descriptor.getMappingForAttributeName("addresses");
       Expression exp = oneToManyMapping.buildSelectionCriteria();
       ExpressionBuilder builder = exp.getBuilder();
       Expression addedExpression = builder.getField("city").equal("New Delhi");
       oneToManyMapping.setSelectionCriteria(exp.and(addedExpression));
 }
}

import org.eclipse.persistence.annotations.Customizer;

@Entity
@Customizer(ec.pack.z.pruebasDesarrollo.DC.class)    
public class Employee {

@Id @GeneratedValue
public long id;

public String name;

@OneToMany
public Collection<Address> addresses = new ArrayList<Address>();
...}