java - 使用 Hibernate Criteria 将 Projection 字段设置为 hibernate 中的外键列

Question

如何将投影字段设置为 hibernate 条件查询中的外键引用。例如，

 Criteria crt = s.createCriteria(UsersforGrades.class).createCriteria("id", "id1").createCriteria("id1.userId", "id2").add(Restrictions.eq("id2.userId", ue.getUserId()));
                ProjectionList proList = Projections.projectionList();
                proList.add(Projections.property("gradeId.gradeId"));

异常:

org.hibernate.QueryException: could not resolve property: gradeId of: com.treamis.entity.UserEntity

Answer 1

尽管回答迟了:(提出了相同的场景)

在这种情况下，您需要创建别名。

criteria.createAlias("gradeId", "gradeId");
criteria.setProjection(Projections.property("gradeId.gradeId"));