Question

所以我试图修改我的模型，现在我无法摆脱这个错误。我试图删除我的所有数据，但它没有帮助。我认为它与我的数据库有关，但在此之前，所有事情都可以正常工作。我收到这个错误：

（1054，“字段列表中的未知栏'courses_course.course_category_id'”）

这是我的模特：

class StudyProgramme(models.Model):
    department = models.ForeignKey('Department', on_delete=models.CASCADE)
    name = models.CharField(max_length=50)
    studies_type = models.IntegerField(choices=((0, "Bachelor Studies"),
                                                (1, "Master Studies"),
                                                (2, "PhD Studies"),
                                                (3, "Integrated Studies")))
    duration = models.PositiveSmallIntegerField(validators=[MaxValueValidator(99)])

    class Meta:
        verbose_name = "Study Programme"
        verbose_name_plural = 'Study Programmes'

    def __str__(self):
        return self.name

class Course(models.Model):
    study_programme = models.ForeignKey('StudyProgramme', on_delete=models.CASCADE)
    course_category = models.ForeignKey('CourseCategory', on_delete=models.CASCADE, default='',
                                        related_name='categories')
    name = models.CharField(max_length=50)
    ects = models.PositiveSmallIntegerField(validators=[MaxValueValidator(99)])
    description = models.TextField()
    year = models.PositiveSmallIntegerField(validators=[MaxValueValidator(99)])
    semester = models.IntegerField(choices=((1, "1"),
                                            (2, "2"),
                                            ), default=None)
    slug = models.SlugField(max_length=140, unique=True)

    def __str__(self):
        return self.name

    def _get_unique_slug(self):
        slug = slugify(self.name)
        unique_slug = slug
        num = 1
        while Course.objects.filter(slug=unique_slug).exists():
            unique_slug = '{}-{}'.format(slug, num)
            num += 1
        return unique_slug

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = self._get_unique_slug()
        super().save()


class CourseCategory(models.Model):
    course_category = models.CharField(max_length=50, unique=True)

    def __str__(self):
        return self.course_category


class Lecture(models.Model):
    course = models.ForeignKey('Course', on_delete=models.CASCADE, default='', related_name='lectures')
    lecture_title = models.CharField(max_length=100)
    content = models.TextField()
    link = models.URLField(blank=True)
    files = models.ManyToManyField('FileUpload', blank=True)

    def __str__(self):
        return self.lecture_title


class FileUpload(models.Model):
    file = models.FileField(upload_to='documents')

    def file_link(self):

        if self.file:
            return "<a href='%s'>download</a>" % (self.file.url,)
        else:
            return "No attachment"

    file_link.allow_tags = True
    file_link.short_description = 'File Download'

Answer 1

我已经通过从mysql shell中删除数据库然后重新创建它来解决了这个问题。

Answer 2

对模型进行任何更改后，您需要运行这两个命令才能将它们反映到数据库中。

python manage.py makemigrations

和

python manage.py migrate

将您的模型类反映到数据库是一个两步过程。从Django Documentation了解有关迁移的详情。

当我尝试在管理面板中访问模型时，来自数据库的错误1054

2 个答案: