[英]Hibernate criteria LEFT JOIN
For a project I want to get a LEFT JOIN working with criteria but I don"t get what I want. 对于一个项目,我想获得一个符合条件的左联接,但我没有得到想要的东西。
I want to do this: Select Books FROM UserBooks LEFT JOIN Books ,.... But I don't get anything. 我要执行以下操作:从UserBooks中选择Books,然后再选择Left .....,但是我什么也没得到。
This is what I got at the moment: 这是我现在得到的:
@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;
}
never mind I got it :) 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 + "%"));
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.