The state field path cannot be resolved to a valid type. JPA query

Question

I'm trying to make a jpa query, but I'm getting an exception:

The state field "n.id" path cannot be resolved to a valid type.

My query is:

select distinct n from News n 
left join n.commentsList as c 
left join n.tagSet as nt 
left join n.author as a 

group by n.id, n.title, n.shortText, n.fullText, n.creationDate,
n.modificationDate, n.author.authorId, n.version 
order by n.modificationDate desc, count(c.news) desc

My entity:

@Entity
@Table(name = "News")
public final class News implements Serializable, IEntity {

/**
 * For deserialization with no exception after modification.
 */
private static final long serialVersionUID = 3773281197317274020L;

@Id
@SequenceGenerator(name = "NEWS_SEQ_GEN", sequenceName = "NEWS_SEQ")
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "NEWS_SEQ_GEN")
@Column(name = "NEWS_ID", precision = 0)
private Long newsId; // Primary key

@Column(name = "TITLE")
private String title;

@Column(name = "SHORT_TEXT")
private String shortText;

@Column(name = "FULL_TEXT")
private String fullText;

@Temporal(TemporalType.DATE)
@Column(name = "CREATION_DATE")
private Date creationDate;

@Temporal(TemporalType.DATE)
@Column(name = "MODIFICATION_DATE")
private Date modificationDate;

@OneToMany(fetch = FetchType.EAGER, mappedBy = "news")
private List<Comment> commentsList;

@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(name = "NEWS_TAG", joinColumns = { @JoinColumn(name = "NEWS_ID") }, inverseJoinColumns = { @JoinColumn(name = "TAG_ID") })
private Set<Tag> tagSet;

@ManyToOne(fetch = FetchType.EAGER)
@JoinTable(name = "NEWS_AUTHOR", joinColumns = { @JoinColumn(name = "NEWS_ID") }, inverseJoinColumns = { @JoinColumn(name = "AUTHOR_ID") })
private Author author;

@Version
private Long version;

I think that there is something wrong in alias and in the group by clause.

Answer 1

Your id is called

private Long newsId; // Primary key

Therefore that is the value you should use in your query. In other words:

group by n.newsId, ...

and not n.Id

I believe you need to adjust your query and just use the n.newsId in your group by clause.

select n, count(c) from News n 
left join n.commentsList as c 
left join n.tagSet as nt 
left join n.author as a 

group by n.id
order by n.modificationDate desc, count(c) desc

I think this will ensure that you can get the counts of the comments (though I'm not certain).