如何创建自定义学生组并将学生添加到该组？答案

【问题标题】：How to create a custom student group and add students to that group?如何创建自定义学生组并将学生添加到该组？
【发布时间】：2022-01-21 13:21:35
【问题描述】：

我正在创建一个学生项目管理系统，每个学生都会有一个项目组。只有管理员才能使用下拉列表菜单将学生添加到特定组。到目前为止，我已经创建了一个学生模型和一个小组模型，例如这些。

class Student(models.Model):
    user = models.OneToOneField(User,null=True,on_delete=models.CASCADE)
    id = models.IntegerField(max_length=11,primary_key=True)
    course_taken = models.CharField(max_length=50,null=True)
    specialization = models.CharField(max_length=50,null=True)
    area_of_interest = models.CharField(max_length=50,null=True) 
    group = models.ForeignKey(Group,null=True)
    def __str__(self):
        if self.user.first_name and self.user.last_name:
            full_name = self.user.first_name + " " + self.user.last_name
        return full_name 

class Group(models.Model):
    id = models.AutoField(primary_key=True)
    members = models.OneToManyField(User,through='Student')
    project_id = models.ForeignKey(Project,null=True)

如何从这里继续？

【问题讨论】：

标签： python django django-models

【解决方案1】：

from django.db import models

class Reporter(models.Model):
    first_name = models.CharField(max_length=30)
    last_name = models.CharField(max_length=30)
    email = models.EmailField()

    def __str__(self):
        return "%s %s" % (self.first_name, self.last_name)

class Article(models.Model):
    headline = models.CharField(max_length=100)
    pub_date = models.DateField()
    reporter = models.ForeignKey(Reporter, on_delete=models.CASCADE)

    def __str__(self):
        return self.headline

    class Meta:
        ordering = ['headline']

如本例所示，您可以通过模型关系（一对一、一对多、多对一、多对多）来做到这一点。我建议查阅文档： https://docs.djangoproject.com/en/4.0/topics/db/examples/many_to_one/

【讨论】：

【解决方案2】：

您必须创建三个不同的类来完成该任务。通过 Enrollment 课程，管理员将能够将学生添加到特定组。

class Student(models.Model):
    name = models.CharField(max_length=30)

    def __str__(self):
        return self.name


class Course(models.Model):
    name = models.CharField(max_length=30)
    student = models.ManyToManyField(Student, through='Enrollment')

    def __str__(self):
        return self.name


class Enrollment(models.Model):
    student = models.ForeignKey(Student, on_delete=models.CASCADE)
    course = models.ForeignKey(Course, on_delete=models.CASCADE)
    date_enrolled = models.DateField()
    final_grade = models.CharField(max_length=1, blank=True, null=True)


    class Meta:
        unique_together = [['student', 'course']]

【讨论】：