Django的南遷移錯誤「包含空值」，使用null =真字段

Question

當添加用於易縮略圖的字段到模型

easy_thumbnail = ThumbnailerImageField(
    null=True, blank=True, verbose_name=_("Easy_Thumbnails"), 
    upload_to="easy_thumbnails", 
    resize_source=dict(size=(100, 100), crop="smart"), 
) 

當執行./manage.py schemamigration test --auto，南產生以下遷移：

def forwards(self, orm): 
    # Adding field 'Test.easy_thumbnail' 
    db.add_column('test_test', 'easy_thumbnail', self.gf('django.db.models.fields.files.ImageField')(), keep_default=False) 
[...] 
models = { 
    'test.test': { 
     'Meta': {'object_name': 'Test'}, 
     'easy_thumbnail': ('django.db.models.fields.files.ImageField', [], {}), 

當執行./manage.py migrate test，我得到這個錯誤：

The error is `django.db.utils.IntegrityError: column "easy_thumbnail" contains null values` 

Answer 1

修改遷移腳本如下解決了這個問題：

• 添加「空=真，空=真」在db.add_column
• 添加「‘空’：‘真’，‘空白’：「真「」在模型[ 'test.test'] [ 'easy_thumbnail']

的代碼：

def forwards(self, orm): 
    # Adding field 'Test.easy_thumbnail' 
    db.add_column('test_test', 'easy_thumbnail', self.gf('django.db.models.fields.files.ImageField')(null=True, blank=True), keep_default=False) 
[...] 
models = { 
    'test.test': { 
     'Meta': {'object_name': 'Test'}, 
     'easy_thumbnail': ('django.db.models.fields.files.ImageField', [], {'null': 'True', 'blank': 'True'}),