Django Postgres完整性錯誤

Question

我在django中創建了一些模型來表示新聞文章，作者以及每篇文章的地理焦點。我需要文章和作者之間的多對多關係，以及文章和位置之間的一對多關係，每個位置可以有多個文章，但反之亦然。我已經試過各種方法，但每次我在Django運行遷移我收到以下錯誤：

django.db.utils.ProgrammingError: multiple default values specified for column "id" of table "location" 

生成表中的代碼如下：

from django.contrib.gis.db import models 

class Article(models.Model): 
    article_id = models.AutoField(primary_key=True) 
    article_title = models.CharField(max_length=200, unique_for_date="pub_date") 
    pub_date = models.DateTimeField('date published') 
    article_summary = models.TextField() 
    title_id = models.CharField(max_length=200) 
    section_id = models.CharField(max_length=200) 

    def __unicode__(self): 
     return u'%s %s' % (self.article_title, self.pub_date)   
    class Meta: 
     db_table = 'article' 


class Author(models.Model): 
    author_id = models.AutoField(primary_key=True) 
    articles = models.ManyToManyField(Article) 
    first_name = models.CharField(max_length=200) 
    last_name = models.CharField(max_length=200) 

    def __unicode__(self): 
     return u'%s %s %s' % (self.articles, self.first_name, self.last_name) 

    class Meta: 
     db_table = 'author' 

class Location(models.Model): 
    location_id = models.AutoField(primary_key=True) 
    lat = models.FloatField() 
    lon = models.FloatField() 
    local = models.CharField(max_length=200) 
    city = models.CharField(max_length=200) 
    region = models.CharField(max_length=200) 
    country = models.CharField(max_length=200) 
    continent = models.CharField(max_length=200) 
    article = models.ForeignKey(Article, default=0) 

    def __unicode__(self): 
     return u'%s %s %s' % (self.location_id, self.lat, self.lon) 

    class Meta: 
     db_table = 'location' 

我想這件事情相對簡單，但它在過去的幾天裏逃脫了我。讓我知道你是否需要更多信息。

這是我現在用的，但上述同樣的問題仍然有機型代碼：

from django.contrib.gis.db import models 

class Author(models.Model): 
    first_name = models.CharField(max_length=200) 
    last_name = models.CharField(max_length=200) 

    def __unicode__(self): 
     return u'%s %s' % (self.first_name, self.last_name)   
    class Meta: 
     db_table = 'author' 


class Location(models.Model): 
    lat = models.FloatField() 
    lon = models.FloatField() 
    local = models.CharField(max_length=200) 
    city = models.CharField(max_length=200) 
    region = models.CharField(max_length=200) 
    country = models.CharField(max_length=200) 
    continent = models.CharField(max_length=200) 

    def __unicode__(self): 
     return u'%s %s' % (self.lat, self.lon)  
    class Meta: 
     db_table = 'location' 


class Article(models.Model): 
    authors = models.ManyToManyField(Author) 
    location = models.ForeignKey(Location) 
    article_title = models.CharField(max_length=200, unique_for_date="pub_date") 
    pub_date = models.DateTimeField('date published') 
    article_summary = models.TextField() 
    title_id = models.CharField(max_length=200) 
    section_id = models.CharField(max_length=200) 

    def __unicode__(self): 
     return u'%s %s' % (self.article_title, self.pub_date)   
    class Meta: 
     db_table = 'article' 

Answer 1

如果一篇文章可以有多個作者，一個位置，那麼你需要的是一個多對一 - 與作者和外鍵的位置有很多關係。

class Article(models.Model): 
    article_id = models.AutoField(primary_key=True) 
    authors = models.ManytoManyField(Author) 
    location = models.ForeignKey(Location) 
    article_title = models.CharField(max_length=200, unique_for_date="pub_date") 
    pub_date = models.DateTimeField('date published') 
    article_summary = models.TextField() 
    title_id = models.CharField(max_length=200) 
    section_id = models.CharField(max_length=200) 

您不需要位置文章Id。

class Location(models.Model): 
    location_id = models.AutoField(primary_key=True) 
    lat = models.FloatField() 
    lon = models.FloatField() 
    local = models.CharField(max_length=200) 
    city = models.CharField(max_length=200) 
    region = models.CharField(max_length=200) 
    country = models.CharField(max_length=200) 
    continent = models.CharField(max_length=200) 

另外值得一提的是，你不必爲您創造模型的ID（它們會自動創建的），除非你想用比模型IDS簡單的整數以外的東西。