使用 activeJDBC 通过 Many2Many 查找记录

【问题标题】：Find records with Many2Many using activeJDBC使用 activeJDBC 通过 Many2Many 查找记录
【发布时间】：2017-08-21 22:04:31
【问题描述】：

我有这些模型的注释：

@Many2Many(other = Course.class, join = "registrations", sourceFKName = "student_uid", targetFKName = "course_uid")
public class Student extends Model {
}

@Many2Many(other = Student.class, join = "registrations", sourceFKName = "course_uid", targetFKName = "student_uid")
public class Course extends Model {
}

如何让所有学生都属于课程 UID？

【问题讨论】：

标签： many-to-many activejdbc javalite

【解决方案1】：

首先，您不需要两次指定相同的注释。这将同样有效：

public class Student extends Model {}

@Many2Many(other = Student.class, join = "registrations", sourceFKName = "course_uid", targetFKName = "student_uid")
public class Course extends Model { }

其次，您的案例在本页描述：http://javalite.io/many_to_many_associations#select-related-objects

所以，你会：

Course course = Course.findById(id);
List<Student> students = course.getAll(Student.class);

就是这样！

【讨论】：