问题描述
我需要过滤对象列表中的实体,例如:
I need to filter an entity in a list of objects, for example:
public class Student {
private int id;
private List<Course> courses;
}
public class Course {
private int id;
private String name;
private float note;
private Classroom classroom;
}
public class Classroom {
private int id;
private String classroom;
}
例如,如何获取位于教室23中的,仅具有大于70的笔记的课程列表的学生对象?
How to obtain a student object with a list of courses with only notes greater than 70, and located in classroom 23 (for example)?
有没有一种方法可以使用实体名称而不是数据库的列之一?
Is there a way to use the name of the entity instead of the one of the column of the database?
或者我该如何与sql关联由hibernate为实体创建的别名?
Or how do I associate with sql the alias generated by hibernate for the entity?
我附上了来自休眠过滤器的链接: https://docs.jboss.org/hibernate/orm/5.0/manual/en-US/html/ch19.html
I attach a link from the hibernate filters:https://docs.jboss.org/hibernate/orm/5.0/manual/en-US/html/ch19.html
推荐答案
好吧,它认为应该可以解决问题:
Ok it think this should do the trick:
实体
public class Student {
private int id;
@OneToMany(mappedBy = "student")
@Filter(name = "defaultCoursesFilter")
private List<Course> courses;
}
@FilterDef(name = "defaultCoursesFilter"
, defaultCondition=" notes > 70")
public class Course {
private int id;
private String name;
private float note;
@ManyToOne
@Filter(name = "defaultClassromFilter")
private Classroom classroom;
}
@FilterDef(name = "defaultClassromFilter"
, defaultCondition=" id = 23")
public class Classroom {
private int id;
private String classroom;
}
查询之前
Session session = sessionFactory.getCurrentSession();
session.enableFilter("defaultCoursesFilter");
session.enableFilter("defaultClassromFilter");
// query
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