使用 activeJDBC 通过 Many2Many 查找记录

Question

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某个课程的 UID？

Answer 1

首先，您不需要指定相同的注解两次。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，此页面描述了您的案例：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);

就这些！

使用 activeJDBC 通过 Many2Many 查找记录

Find records with Many2Many using activeJDBC

many-to-many

activejdbc

javalite