Question

我有两个模型，我想得到 - 模型1的一些字段到模型2.我正在使用

field in model 2 = models.ForeignKey(model1, to_field = 'field i want from model 1')

我在控制台中收到的错误是

myapp.IFileTable.calendar_year: (fields.E304) Reverse accessor for 'IFileTable.calendar_year' clashes with reverse accessor for 'IFileTable.created_on'.
            HINT: Add or change a related_name argument to the definition for 'IFileTable.calendar_year' or 'IFileTable.created_on'.

lfcalendar.IFileTable.title: (fields.E311) 'IFile.title' must set unique=True because it is referenced by a foreign key.

我的模特1

class IFile(models.Model):
    title = models.CharField(max_length=255, blank=True)
    year = models.CharField(max_length=4)
    uploaded_at = models.DateTimeField(auto_now_add=True)

我的模特2

class IFileTable(models.Model):
    title = models.ForeignKey(IntermediateFile, to_field = 'title')
    user = models.CharField(max_length = 10)
    created_on = models.ForeignKey(IntermediateFile, to_field = 'uploaded_at')
    calendar_year = models.ForeignKey(IntermediateFile, to_field = 'year')

Answer 1

我认为你误解了外键的作用。它们允许您访问相关模型的整个实例，而不是单个字段。除非您希望它们指向不同的实例，否则没有理由让两个或三个FK指向同一个模型，但即使这样，您也不需要使用不同的to_field值。

你的模特应该是：

class IFileTable(models.Model):
    intermediate_file = models.ForeignKey(IntermediateFile)

现在，给定IFileTable的实例，你可以这样做：

my_ifiletable.intermediate_file.title
my_ifiletable.intermediate_file.year
my_ifiletable.intermediate_file.uploaded_at

django中不同模型字段的外键

1 个答案: