java 如何使用 JpaRepository 和嵌套的对象列表进行搜索？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/47996810/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to search with JpaRepository and nested list of objects?
提问by DevDio
Description
描述
There is a PersonRepositoryand Personentity,
Personclass contains List<Qualification>. Qualificationclass has 3 simple fields.
有一个PersonRepositoryandPerson实体，
Person类包含List<Qualification>. Qualification类有 3 个简单的字段。
I have tried to add @Queryannotation on custom method and use JPQL to get the results, but Qualificationclass fields were not available for manipulation in JPQL as it repository itself contains List<Qualification>instead of just a simple field of Qualification.
我尝试@Query在自定义方法上添加注释并使用 JPQL 来获取结果，但是Qualification类字段不可用于在 JPQL 中进行操作，因为它存储库本身包含List<Qualification>而不仅仅是一个简单的Qualification.
How can I search by these Qualification's nested fields?
如何通过这些 Qualification 的嵌套字段进行搜索？
Query
询问
Now I need to find list of person entity where qualification's experienceInMonths is greater than 3 and less than 9 AND qualification's name field = 'java'.
现在我需要找到资格的 ExperienceInMonths 大于 3 且小于 9 且资格的名称字段 = 'java' 的人员实体列表。
Code
代码
Person.java
人.java
@Data
@Entity
public class Person {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private String id;
@NotEmpty
@Size(min = 2)
private String name;
@NotEmpty
@Size(min = 2)
private String surname;
@ElementCollection(targetClass = java.util.ArrayList.class, fetch = FetchType.EAGER)
private List<Qualification> qualifications = new ArrayList<>();
}
PersonRepository.java
PersonRepository.java
@Repository
public interface PersonRepository extends JpaRepository<Person, String> {
}
Qualification.java
资质.java
@Data
@AllArgsConstructor
public class Qualification implements Serializable {
@Id @GeneratedValue
private String id;
private String name;
private String experienceInMonths;
}
EDIT:not duplicate of this post, as here is the collection of nested objects. Not just single reference.
编辑：不是这篇文章的重复，因为这里是嵌套对象的集合。不仅仅是单一的参考。
回答by Cepr0
First, change experienceInMonthsfrom Stringto int(otherwise you can not compare the string with the number). Then you can try to use this 'sausage':
首先，改变experienceInMonths从String到int（否则你不能比较数字字符串）。然后你可以尝试使用这个“香肠”：
List<Person> findByQualifications_experienceInMonthsGreaterThanAndQualifications_experienceInMonthsLessThanAndName(int experienceGreater, int experienceLess, String name);
Or you can try to use this pretty nice method:
或者你可以尝试使用这个非常好的方法：
@Query("select p from Person p left join p.qualifications q where q.experienceInMonths > ?1 and q.experienceInMonths < ?2 and q.name = ?3")
List<Person> findByQualification(int experienceGreater, int experienceLess, String name);
