如何将管理员中的“无”更改为“

Question

如何在我的表中禁用None，表AUTORDOCUMENT只有外键。

我试过admin.py：

from django.contrib.admin.views import main

class MyModelAdmin(admin.ModelAdmin):
    def __init__(self,*args,**kwargs):
         super(MyModelAdmin, self).__init__(*args, **kwargs)
         main.EMPTY_CHANGELIST_VALUE = ''

但我仍然没有

models.py

class AutorDocument(models.Model):  
     idAuthor=models.ForeignKey(Author,on_delete=models.CASCADE,null=True,verbose_name ='Author')  

   document=models.ForeignKey(Document,on_delete=models.CASCADE,null=True,verbose_name='title')

    def __str__(self):
        return  unicode(self.idAutor)+' Titulo tesis: '+ unicode(self.tesis)

    def __unicode__(self):
        return smart_unicode(('%s %s' % (self.idAutor,self.tesis) ))

class Author(models.Model):
    Firtname=models.CharField(max_length=50)    
    middlename=models.CharField(max_length=50,null=True, blank=True)
    secondsurname=models.CharField(max_length=30)
    lastName=models.CharField(max_length=30)

    def __str__(self):
       return  unicode(self.lastName)+' '+ 
       unicode(self.secondsurname)+' '+unicode(self.Firtname)

    def __unicode__(self):
       return smart_unicode(('%s %s %s %s' % 
       (self.Firtname,self.middlename,self.secondsurname,self.lastName) ))

class Document(models.Model):
    title=models.CharField(max_length=200,primary_key=True)


    def __str__(self):
        return self.titulo

    def __unicode__(self):
        return smart_unicode(('%s' % (self.titulo) ))

作者和文档是AuthorDocument

引用的模型

Answer 1

[ "Text...", "Other text...", "ok", "ok Another text..." ]