Spring：JPA将本机SQL转换为非实体pojo

Question

我有本机SQL，它返回对象集合，我想将结果作为对象集合（一个非实体的pojo类）

is it possible to get the results from native SQL as collection of non entity?

I am using spring jpa 1.10

Answer 1

无法在JPA 1中映射非实体类。

从JPA 2.1开始，您可以使用ConstructorResult与SqlResultSetMapping注释结合使用，将SQL查询的SELECT子句映射到构造函数。

以下是示例

Query q = em.createNativeQuery(
      "SELECT c.id, c.name, COUNT(o) as orderCount, AVG(o.price) AS avgOrder " +
      "FROM Customer c, Orders o " +
      "WHERE o.cid = c.id " +
      "GROUP BY c.id, c.name",
      "CustomerDetailsResult");

   @SqlResultSetMapping(
       name="CustomerDetailsResult",
       classes={
          @ConstructorResult(
               targetClass=com.acme.CustomerDetails.class,
                 columns={
                    @ColumnResult(name="id"),
                    @ColumnResult(name="name"),
                    @ColumnResult(name="orderCount"),
                    @ColumnResult(name="avgOrder", type=Double.class)
                    }
          )
       }
      )

Answer 2

Mapping NativeQuery results into a POJO-这是使用@JsonFormat和ObjectMapper的JPA独立解决方案，其代码示例详细介绍了已经提到的@ darshan-patel。