使用@Query休眠jpa投影 [英] hibernate jpa projection with @Query

问题描述

我看到的大多数示例都是使用entityManager.createQuery或.createNativeQuery等.

Most of the examples I've seen is using entityManager.createQuery or .createNativeQuery etc.

有没有办法使以下工作正常?

Is there a way to have something like the following working?

data class SummaryDto(val employeeName: String, val employerName: String)

@Query("select e.name as employeeName, emp.name as employerName " +
            "from Employer e " +
            "inner join Employee emp on emp.employer_id = e.id ", nativeQuery = true)
    fun findSummaries(): List<SummaryDto>

当我运行上面的代码时

我收到此错误 找不到能够从类型转换的转换器 [org.springframework.data.jpa.repository.query.AbstractJpaQuery$TupleConverter$TupleBackedMap] to type [dto.SummaryDto]

I got this error No converter found capable of converting from type [org.springframework.data.jpa.repository.query.AbstractJpaQuery$TupleConverter$TupleBackedMap] to type [dto.SummaryDto]

这可以用Kotlin完成吗，还是有另一种方法可以使它与基于Hibernate JPA Annotation一起使用?

Can this be done with Kotlin or is there another way to get this to work with Hibernate JPA Annotation based?

谢谢 锡

推荐答案

针对可能会遇到相同问题的任何人.将SummaryDto更改为这样的界面

For anyone that might run into the same problem. Change SummaryDto to an interface like this

interface SummaryDto { val employeeName: String val employerName: String }

interface SummaryDto { val employeeName: String val employerName: String }

将起作用.

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