休眠条件 LEFT JOIN

Question

对于一个项目，我想获得一个符合标准的 LEFT JOIN，但我没有得到我想要的。

我想这样做：Select Books FROM UserBooks LEFT JOIN Books ,.... 但我什么也没得到。

这是我目前得到的：

@SuppressWarnings("unchecked")
public List<Books> getBooksByTitle(int userID, String Title) {
    List<Books> books = null;

    Configuration cfg = new Configuration();
    cfg.configure("hibernate.cfg.xml");
    SessionFactory factory = cfg.buildSessionFactory();
    Session session = factory.openSession();
    Transaction tx = session.beginTransaction();

    Criteria c = session.createCriteria(UserBooks.class, "userBooks");
    c.setFetchMode("userBooks.book", FetchMode.JOIN);
    c.createAlias("userBooks.book", "books");
    c.setProjection(Projections.property( "books") ) ;
    c.add(Restrictions.eq("userBooks.id", userID));
    c.add(Restrictions.like("books.title", "%"+ Title + "%"));

    books = c.list();

    for (Books allBooks : (List<Books>)books) {
              System.out.println(">>>>>" + allBooks.getTitle()); 
    }

    tx.rollback();
    session.close();
    factory.close();
    return books;
}

Answer 1

没关系，我明白了:)

Criteria c = session.createCriteria(UserBooks.class, "userBooks");
    c.createAlias("userBooks.book", "book");
    c.setProjection(Projections.property("book"));
    c.add(Restrictions.eq("userBooks.user.id", userID));
    c.add(Restrictions.like("book.title", "%" + Title + "%"));