Question

I have a book entity which has a OneToMany relationship set up to Document entity. In other words, in Hibernate, my book entity returns a list of Documents as the property docs.

I want to return a list of documents for a user which have not been assigned to a book, yet. Here is my jpql query, and I’ve finagled it every way I can, and I can’t get it to work:

select d from Document d WHERE d.user = :user
AND NOT EXISTS( SELECT b.docs from Book b WHERE b.docs = d )

Where Book is an entity, User is an entity passed in, b.docs is a list of Documents, and Document(d) is an entity.

What am I doing wrong? With this particular version of the query, I’m receiving the error:

org.hibernate.TypeMismatchException: left and right hand sides of a binary logic
operator were incompatibile
[java.util.Collection(com.fallenjusticestudios.bardwalk.model.Book.docs) : com.fallenjusticestudios.bardwalk.model.Document]

Book:

@Entity
@Table(name="book")
public class Book {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Long id;

    @Column
    @NotEmpty
    @NotNull
    private String title;

    @Column
    @NotEmpty
    @NotNull
    private String description;

    @ManyToOne(cascade=CascadeType.MERGE, targetEntity=User.class)
    @JoinColumn(name="user")
    private User user;

    @OneToMany(cascade=CascadeType.MERGE, fetch=FetchType.LAZY, targetEntity=Document.class)
    @JoinColumn(name="document_id",referencedColumnName="id")
    private List<Document> docs;


    // Will need to add Contest to the fields later on.
    //
    //


    public Long getId() {
        return id;
    }

    public String getTitle() {
        return title;
    }

    public String getDescription() {
        return description;
    }

    public User getUser() {
        return user;
    }

    public List<Document> getDocs() {
        return docs;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public void setDocs(List<Document> docs) {
        this.docs = docs;
    }





}

UPDATE:

Another try:

Query:

select d from Document d WHERE d.user = :user
AND NOT EXISTS( SELECT Document from Book.docs b WHERE b.id = dn.id )

org.hibernate.hql.ast.QuerySyntaxException: Book.docs is not mapped [select d from com.fallenjusticestudios.bardwalk.model.Document d WHERE d.user = :user AND NOT EXISTS( SELECT Document from Book.docs b WHERE b.id = dn.id)]

UPDATE2:

I figured this out. I was going about the query all wrong. Solution query was:

select d from Document d WHERE d.user = :user
AND NOT d IN( SELECT d from Book b, IN(b.docs) bd WHERE bd.id = d.id )

Answer 1

I figured this out. I was going about the query all wrong. Solution query was:

select d from Document d WHERE d.user = :user
AND NOT d IN( SELECT d from Book b, IN(b.docs) bd WHERE bd.id = d.id )