如何通过Django上的表单将对象添加到多对多关系中?

我有以下型号:

class Exercise(models.Model):
    exercise = models.CharField(max_length=166)
    series = models.CharField(max_length=2)
    reps = models.CharField(max_length=2)
    station = models.ForeignKey(Station)


class Workout(models.Model):
    member = models.ForeignKey(Member, on_delete=models.CASCADE)
    day = models.CharField(max_length=1)
    exercises = models.ManyToManyField(Exercise)

我希望能有一个页面,每个 Workout 显示,用户可以添加 Exercises 单击+按钮时。

所以,这需要 训练 URL中的ID,以及创建 Exercise 会自动将其与该训练关联。

我尝试过这方面的东西,但我觉得不管用:

if request.method == 'POST':
        np_form = NewWorkout(request.POST)
        ne_form = NovoExercise(request.POST)
    
        if ne_form.is_valid() and np_form.is_valid():
            nesave = ne_form.save()
            npsave = np_form.save(commit = False)
            npsave.exercises = nesave
            npsave.save()