Spring数据Jpa在select查询中使用new关键字

Question

我已经看过像这样的JPQL查询

SELECT new path.to.dto.MyDto(e.id, e.otherProperty) FROM Student e WHERE e.id = ?1

我能用这种方式写点什么吗？

SELECT new path.to.dto.MyDto(e.id, new path.to.dto.OtherDTO) FROM Student e WHERE e.id = ?1

Answer 1

也许你应该使用这样的查询：

SELECT new path.to.dto.MyDto(e.id, e.otherDtoParam1, e.otherDtoParam2,...) FROM Student e

并实现MyDto的构造函数：

public MyDto(Integer id, Object otherDtoParam1, Object otherDtoParam2, ...) {
    this.id = id;
    this.otherDto = new OtherDto(otherDtoParam1, otherDtoParam2, ...)
    ...
}