Java 在同一存储库中创建JPA投影

我想创建这个JPA投影：

@Repository
public interface PaymentTransactionRepository extends JpaRepository<PaymentTransactions, Integer>, JpaSpecificationExecutor<PaymentTransactions> {

    @Query(value = "SELECT count(id) as count, status, error_class, error_message, id FROM " +
            " payment_transactions " +
            " WHERE terminal_id = :id AND (created_at > :created_at) "      List<PaymentTransactionsDeclineReasonsDTO> transaction_decline_reasons(@Param("id") Integer transaction_unique_id, @Param("created_at") LocalDateTime created_at);
}

public interface PaymentTransactionsDeclineReasonsDTO {
    int getId();
    int getCount();
    //... and so on
}

但我有例外

org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [org.springframework.data.jpa.repository.query.AbstractJpaQuery$TupleConverter$TupleBackedMap] to type [org.plugin.service.PaymentTransactionsDeclineReasonsDTO]

你知道我如何解决这个问题吗？我想我必须创建一个单独的存储库

扩展JpaRepository

---

但我希望使用相同的存储库，因为我有使用适当实体的查询。有什么解决方案吗？

您应该能够使用普通投影作为界面来实现这一点。 您可以找到一个关于如何设置基于界面的投影的好教程。 基本上，您可以将

PaymentTransactionDeclineReasonsTo

转换为一个接口，并声明要通过投影访问的getter：

@Repository
public interface PaymentTransactionRepository extends JpaRepository<PaymentTransactions, Integer>, JpaSpecificationExecutor<PaymentTransactions> {

    @Query(value = "SELECT count(id) as count, status, error_class, error_message, id FROM " +
            " payment_transactions " +
            " WHERE terminal_id = :id AND (created_at > :created_at) "      List<PaymentTransactionsDeclineReasonsDTO> transaction_decline_reasons(@Param("id") Integer transaction_unique_id, @Param("created_at") LocalDateTime created_at);
}

public interface PaymentTransactionsDeclineReasonsDTO {
    int getId();
    int getCount();
    //... and so on
}

这样，您仍然可以使用相同的存储库，但只能获取实际类的选定属性