Spring数据JPA:按列查找自定义类类型的成员 [英] Spring data JPA: find by column of custom class type's member

问题描述

我有一个实体Person，其属性为Name.名称未标记为实体.对于Name类，我有一个AttributeConverter，它通过姓和名的字符串连接来创建全名.因此，对于人员实体，列名称的类型为字符串.

I have an entity Person which has a property Name. Name is not marked as entity. For the Name class I have an AttributeConverter which creates a full name by string concatenation of first and last name. So for the person entity the column name is of type String.

@Entity
public class Person {
    // ...  
@Convert(converter = NameAttributeConverter.class)
@Column

private Name name;
    // ...
}

public final class Name implements Comparable, Serializable {
      // ...
      private String firstName;
      private String lastName;
      // ...
}

这有效.但是现在我想扩展我的人员存储库.我想按她的姓氏查找人.但是

This works. But now I want to extend my person repository. I want to find persons by her lastName. But

List<Person> findByName_LastName(String lastName);

或

List<Person> findByNameLastName(String lastName);

不起作用.我收到以下异常:

does not work. I get the following exception:

PersonRepository.findByName_LastName(java.lang.String)! Illegal attempt to dereference path source [null.name] of basic type

我该如何解决该问题?谢谢和问候

How can I solve the problem? Thanks and regards

public interface PersonRepository extends CrudRepository<Person, Long>{
    // The repository works without the findByName...
    // List<Person> findByName_LastName(String lastName);
}

推荐答案

您将名字和姓氏视为数据库中的一列，因为您对 name 列使用了属性转换器.因此，JPA将 name 视为类型为 Name 的列，并且无法在 Name 对象类型字段上进行查询.更好的解决方案是将名字和姓氏存储在单独的列中，以便您轻松查询.但是，如果您想创建一个姓和名的字段连续查询并查询连续字段，则可以使用 @Formula()

You treat firstname and lastname as a column in database since you use Attribute converter for name column. So JPA treats name as a column of type Name and can't do query on Name object type field. The better solution is to store firstname and lastname in a separate column so that you can query easily. But if you want make a field concat of firstname and lastname and query on concat field also then you can use @Formula()

@Column(name = "first_name")
private String firstName;

@Column(name = "last_name")
private String lastName;

@Formula(value = "CONCAT(last_name, first_name)")
private String name;

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