Django 按用户名或id获取帖子

我有这个型号

class Post(models.Model):   
    auth = models.ForeignKey(settings.AUTH_USER_MODEL,default=1)    
    title = models.CharField(max_length=120)    
    DESCSPECSOFT = (
    (u'Null','Null'),
    (u'Phone',u'Phone'),
    (u'Car',u'Car'),
    (u'Laptop',u'Laptop'),
    (u'jops',u'Jops'),
    (u'Electronic',u'Electronic'),
    (u'Clothes',u'Clothes'),
    (u'Makeup',u'Makeup'),
    (u'Furnishings',u'Furnishings'),
    (u'books',u'books'),
    (u'sports',u'sports'),
    (u'Property',u'Property'),
    (u'Other',u'Other'),
    )   
    City = (
    (u'Null','Null'),
    (u'Kosti',u'Kosti'),
    (u'Khartoum',u'Khartoum'),
    (u'Rabbik',u'Rabbik'),
    (u'Duwaim',u'Duwaim'),
    (u'Sinnar',u'Sinnar'),
    (u'Bahri',u'Bahri'),
    (u'Omdurman',u'Omdurman'),
    (u'Sawakin',u'Sawakin'),
    (u'Port Sudan',u'Port Sudan'),
    (u'Kasala',u'Kasala'),
    (u'Madani',u'Madani'),
    (u'Alabid',u'Alabid'),
    )  
    Case = (
    (u'Null','Null'),
    (u'New',u'New'),
    (u'Old',u'Old'),
    (u'Second Hand',u'Second Hand'),
    (u'Other',u'Other'),
    ) 

    Type = models.CharField(choices=DESCSPECSOFT, default='Null',blank = False,null = False,max_length=120)     
    company = models.CharField(max_length=120)  
    dis = models.TextField(default="in here you w,ll write all the discribtion about your product")     
    image = models.ImageField(null=True,blank=True,width_field="width_field", height_field="height_field")  
    width_field = models.IntegerField(default=0)    
    height_field = models.IntegerField(default=0)   
    case = models.CharField(choices=Case, default=99,blank = False,null = False,max_length=120)     
    price = models.BigIntegerField(default=0)   
    city = models.CharField(choices=City, default='Null',blank = False,null = False,max_length=120)     
    address = models.CharField(max_length=120)  
    draft = models.BooleanField(default=False)  
    #pup = models.DateField(auto_now=False,auto_now_add=False ,null=False)  
    date = models.DateTimeField(auto_now=True ,auto_now_add=False)  
    puplis = models.DateTimeField(auto_now=False ,auto_now_add=True)

    objects = PostManager()

    def __str__(self):      
        return self.title

    def __unicode__(self):      
        return self.title

任何用户都可以添加帖子，但我希望数据库中显示的用户名意味着用户如何添加帖子，因为每个帖子都显示管理员姓名，而不是用户如何添加帖子有人可以告诉我如何修复此问题吗？？？

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对不起，我的en不好…

您好，请您重写您的模型详细信息，并告诉我您必须做什么。我有字段名auth，它的用户字段的默认值为1。一是指管理员我希望该值随用户更改如何登录和添加post从字段中删除默认值并添加null=True，blank=True，当您将数据保存到表中时，添加用户或从“user”表中选择用户。（settings.AUTH\u user\u MODEL）如何？我可以选择用户吗？