python之ContentFile 未保存在 Django 模型 FileField 中

在我的 Django 模型中将字符串保存为文件时遇到问题，因为每当我尝试取回数据时，它都会给我一个 ValueError(“属性没有关联的文件”)。详情如下:

型号:

class GeojsonData(models.Model): 
dname = models.CharField(max_length=200, unique=True) 
gdata = models.FileField(upload_to='data') 
def __str__(self): 
    return self.dname 

保存数据的代码:

cf = ContentFile(stringToBeSaved) 
gj = GeojsonDatua(dname = namevar, gdata = cf) 
gj.save() 

试图读取数据的代码:

def readGeo(data): 
    f = GeojsonData.objects.all().get(id=data.id).gdata 
    f.open(mode ='rb') 
    geo = f.read() 
    return geo 

回溯:

File "C:\Python\Python36-32\lib\site-packages\django\core\handlers\exception.py" in inner 
  41.             response = get_response(request) 
 
File "C:\Python\Python36-32\lib\site-packages\django\core\handlers\base.py" in _get_response 
  187.                 response = self.process_exception_by_middleware(e, request) 
 
File "C:\Python\Python36-32\lib\site-packages\django\core\handlers\base.py" in _get_response 
  185.                 response = wrapped_callback(request, *callback_args, **callback_kwargs) 
 
File "C:\Python\Python36-32\lib\site-packages\django\contrib\auth\decorators.py" in _wrapped_view 
  23.                 return view_func(request, *args, **kwargs) 
 
File "C:\app\views.py" in mapa 
  80.           geostr = app.readGeo.readGeo(d) 
 
File "C:\app\readGeo.py" in readGeo 
  6.    f.open(mode ='rb') 
 
File "C:\Python\Python36-32\lib\site-packages\django\db\models\fields\files.py" in open 
  80.         self._require_file() 
 
File "C:Python\Python36-32\lib\site-packages\django\db\models\fields\files.py" in _require_file 
  46.             raise ValueError("The '%s' attribute has no file associated with it." % self.field.name) 
 
Exception Type: ValueError at /app/map/1 
Exception Value: The 'gdata' attribute has no file associated with it. 

请您参考如下方法:

您需要将 ContentFile 保存为实际文件。与其直接将其分配给字段，不如调用字段的 save 方法并将其传入:

gj = GeojsonDatua(dname = namevar) 
gj.gdata.save('myfilename', cf) 

参见 the docs .

另请注意，如果您总是像这样创建 gdata 字段，您可能根本不需要 FileField；也许改用 TextField。