JPQL select 查询，无法分组

Question

下班后我似乎找不到实现此目的的方法，我有 2 个实体：

public class Price{
@Id
int id;

@Temporal(TemporalType.DATE)
private Date dtComu;

private String descCarb;

private Double price;

//bi-directional many-to-one association to Distributor
@ManyToOne
@JoinColumn(name="idImpiant")
private Distributor distributor;

和

public class Distributor{

@Id
private int idImpiant;

private String province;

//bi-directional many-to-one association to Price
@OneToMany(mappedBy="distributor")
private List<Price> prices;

我要做的事情看起来很简单，为每个分销商获取最新的价格。我想的是获得一份价格清单（每个价格都有一个分销商），按日期排序并按分销商分组。我的查询是：

SELECT e FROM Price e JOIN e.distributor d WHERE e.descCarb like '%Diesel%' group by e.distributor order by e.dtComu desc

我得到的错误是：

SELECT list is not in GROUP BY clause and contains nonaggregated column 'price0_.id' which is not functionally dependent on columns in GROUP BY clause

有没有其他我没想过的方法来实现这个目标？

Answer 1

您看到的错误是因为您不清楚每个经销商组需要哪个实体。这是使用 HQL 执行此操作的一种方法：

select e FROM Price e JOIN e.distributor d
where e.descCarb like '%Diesel%' and
      e.dtComu = (select max(ee.dtComu) from Price ee where ee.distributor = e.distributor)

这使用相关子查询来检查匹配的 Price 实体是否是每个分销商的最新实体。

JPQL select 查询，无法分组

JPQL select query, unable to Group By

java

mysql

jpa

jpql