Hibernate条件：dto作为实体

Question

我有一个用Hibernate标准构建的查询（我只向您展示了“主要”部分）：

Criteria criteria = sessionProvider.get().createCriteria(User.class);
// Add other stuff to the query like joins, group-bys, order-bys etc.
// In the projection list add the "id" of the user.
projectionList.add(Projections.property("id"), "id");
// finally using same entity class User as dto
criteria.setResultTransformer(Transformers.aliasToBean(User.class));

所以我终于可以做：

List<User> users = criteria.list();

users.get(0).getFirstName();

返回NULL。因此，基本上，由Transformers.AliastoBean创建的实体（通过projection只接收到“ID”）不像由get/load/等加载的普通实体那样工作。

有没有办法让这些dto作为实体“工作”呢？

Answer 1

在projectionList中传递参数似乎是错误的，您需要像这样修改projectionList。

Criteria criteria = sessionProvider.get().createCriteria(User.class);
//Add other stuff to the query like joins, group-bys, order-bys etc.

//In the projection list add the columns name which are mapped with the entity
ProjectionList projectionList = Projections.projectionList();
projectionList.add(Projections.property("id"));
projectionList.add(Projections.property("firstName"));
criteria.setProjection(projectionList);

List<User> results = criteria.list();

//output results
for(User user : results) {
    user.getFirstName();        
}