Hibernate Criteria API多次聯接

Question

我的休眠實體如下：

@Entity
@Table(name = "EditLocks")
public class EditLock extends AuditableEntity {

    /** The document that is checked out. */
    @OneToOne
    @JoinColumn(name = "documentId", nullable = false)
    private Document document;

然后，文檔如下所示：

public class Document extends AuditableEntity {
    /** Type of the document. */
    @ManyToOne
    @JoinColumn(name = "documentTypeId", nullable = false)
    private DocumentType documentType;

本質上，我要編寫的查詢是：

Select * from EditLocks el, Document docs, DocumentTypes dt where el.documentId = docs.id and docs.documentTypeId = dt.id and dt.id = 'xysz';

我該如何使用休眠條件API？

Answer 1

應該這樣做：

Criteria criteria = getSession().createCriteria(EditLock.class);
criteria.createAlias( "document", "document" );
criteria.createAlias( "document.documentType", "documentType" );
criteria.add(Restrictions.eq("documenttype.id", "xyz");

您需要添加別名才能到達具有要查詢其屬性的對象。

Answer 2

因此，看來您只是在嘗試獲取具有DocumentType id ='xyz'的Document的EditLocks。 我假設Document和DocumentType具有標准的Hibernate映射：

Criteria crit = getSession().createCriteria(EditLock.class);
crit.add(Restrictions.eq("document.documenttype.id", "xyz");

我認為，Hibernate應該能夠為您找出聯接。