Django：兩個字段是唯一的，但仍然失敗UNIQUE約束

Question

我在寫一些測試來檢查我的基本博客應用程序的模型。該模型要求博客標題是唯一的。以下是我已經寫了節省2篇博客文章測試的身體：

first_post.title = "First Post!" 
    first_post.body = "This is the body of the first post" 
    first_post.pub_date = datetime.date.today() 
    first_post.tags = all_tags[0] 
    first_post.slug = "first_post" 
    first_post.save() 


    second_post = Post() 
    second_post.title = "Second Post!" 
    self.assertNotEqual(first_post.title,second_post.title) 
    second_post.body = "This is the body of the Second post" 
    second_post.pub_date = datetime.date.today() 
    second_post.tags = all_tags[1] 
    second_post.slug = "second" 
    second_post.save() 

注意self.assertNotEqual(first_post.title, second_post.title)。我加了這個，因爲當我運行測試時，我總是收到django.db.utils.IntegrityError: UNIQUE constraint failed: blog_post.title_text。當我通過吐出的這個吐出口的剩餘部分完成時，它指向second_post.save()。但是，assertNotEqual總是通過，如果我將其更改爲assertEqual，則會失敗。

無論我把什麼放入標題值，我都會得到相同的錯誤。爲什麼這兩個Post對象被認爲具有相同的標題？

僅供參考，這裏是博客模式：

class Post(models.Model): 
    title_text = models.CharField(max_length = 200, unique = True) 
    pub_date = models.DateTimeField('date published') 
    post_tags = models.ManyToManyField('Tag') 
    post_body = models.TextField() 
    slug = models.SlugField(max_length = 50, unique = True) 

Answer 1

領域模型中的被命名爲title_text，但在測試使用title。因此，在這兩種情況下，db的值爲title_text。

改成這樣：

first_post.title_text = "First Post!" 
first_post.body = "This is the body of the first post" 
first_post.pub_date = datetime.date.today() 
first_post.tags = all_tags[0] 
first_post.slug = "first_post" 
first_post.save() 


second_post = Post() 
second_post.title_text = "Second Post!" 
self.assertNotEqual(first_post.title_text,second_post.title_text) 
second_post.body = "This is the body of the Second post" 
second_post.pub_date = datetime.date.today() 
second_post.tags = all_tags[1] 
second_post.slug = "second" 
second_post.save()