python - 我如何在 Django 中获取多对多关系表数据？

Question

这是我的模型.py

from django.db import models

class Course(models.Model):
    Credits = (
        ('1', '0.75'),
        ('2', '1'),
        ('3', '2'),
        ('4', '3'),
        ('5', '4'),
        ('6', '5'),
        ('7', '6'),
    )

    course_code = models.CharField(max_length=20, default="CSE-101", unique=True)
    course_name = models.CharField(max_length=50, default="C Language", unique=True)
    course_credit = models.CharField(max_length=1, choices=Credits, default='4')

    def __str__(self):
        return self.course_code


class Student(models.Model):
    std_name = models.CharField(max_length=40)
    std_id = models.CharField(max_length=50, primary_key=True)
    std_email = models.EmailField(max_length=50, unique=True, blank=True)

    course = models.ManyToManyField(Course)

    def __str__(self):
        return self.std_id

当我在Student表中输入数据时，数据库创建了一个表student_course，我想获取这个student_course数据。

我想获取每个学生注册了多少门类(class)以及每个类(class)名称的数据。我如何获取这些数据并在网页中显示这些数据？

我是 python 和 Django 的菜鸟，所以非常感谢任何帮助。

Answer 1

i want to get this student_course data -> 要访问学生表中的相关对象，您可以像这样访问 Student.course.all()

---

I want to get data each student how many course they registered and each course name -> 您可以通过像这样过滤Student对象来检索每个学生的类(class)

student = Student.objects.get(std_id=_place_student_id_here_)
courses = student.course.all() # this will return all courses related to perticular student

---

更新

如果您想为所有用户获取类(class)，您必须这样做

students = Student.objects.all()
for student in students:
    print(student.course.all()) # this will return all courses for this student

如果你想在模板中重新阅读类(class)，就这样做

在你的 views.py

def myview(request):
    students = Student.objects.all()
    return render(request, "studentlist.html",{'students':students})

在您的studentlist.html

{% for student in students %}
  <p>Student Name : {{student.std_name}}<p>
  <p>Courses : 
   {% for course in student.course.all %}
     <span>{{course.course_name}}</span>
   {% endfor %}
  </p>
{% endfor %}