加載不同的值到ModelChoiceField的Django表單

Question

我試圖值的不同列表加載到ModelChoiceField。

class myform(ModelForm): 
    content = forms.FileField() 
    def distinct_mans(): 
     manufacturers = UniPart.objects.all().values('manufacturer').distinct() 
     return manufacturers 
    manufacturer = forms.ModelChoiceField(queryset=distinct_mans) 

要說明，製造商是UniPart表中的一個字段。我想要獲得所有不同的製造商並將其放入下拉菜單中。

但是我得到這個錯誤：

'function' object has no attribute 'all' 

回溯：

Template error: 
In template /Users/nb/Desktop/modelstore/mymodels/templates/mymodels/add_model.html, error at line 24 
    'function' object has no attribute 'all' 
    14 :    {% csrf_token %} 


    15 :    <br> 


    16 :    <div style="float: left; width: 200px"> 


    17 :    <h6>Model Name</h6> 


    18 :    <br> 


    19 :    {{ formtoaddmodel.modelname }} 


    20 :    <br> 


    21 :    <br> 


    22 :    <h6>Manufacturer</h6> 


    23 :    <br> 


    24 :    {{ formtoaddmodel.manufacturer }} 



Traceback: 

    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response 
     111.       response = callback(request, *callback_args, **callback_kwargs) 
    File "/Users/nb/Desktop/modelstore/mymodels/views.py" in add_model 
     652.   }, context_instance=RequestContext(request,{})) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/shortcuts/__init__.py" in render_to_response 
     20.  return HttpResponse(loader.render_to_string(*args, **kwargs), **httpresponse_kwargs) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/loader.py" in render_to_string 
     176.   return t.render(context_instance) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/base.py" in render 
     140.    return self._render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/test/utils.py" in instrumented_test_render 
     62.  return self.nodelist.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/base.py" in render 
     823.     bit = self.render_node(node, context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/debug.py" in render_node 
     74.    return node.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/loader_tags.py" in render 
     123.   return compiled_parent._render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/test/utils.py" in instrumented_test_render 
     62.  return self.nodelist.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/base.py" in render 
     823.     bit = self.render_node(node, context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/debug.py" in render_node 
     74.    return node.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/loader_tags.py" in render 
     123.   return compiled_parent._render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/test/utils.py" in instrumented_test_render 
     62.  return self.nodelist.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/base.py" in render 
     823.     bit = self.render_node(node, context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/debug.py" in render_node 
     74.    return node.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/loader_tags.py" in render 
     123.   return compiled_parent._render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/test/utils.py" in instrumented_test_render 
     62.  return self.nodelist.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/base.py" in render 
     823.     bit = self.render_node(node, context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/debug.py" in render_node 
     74.    return node.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/loader_tags.py" in render 
     62.    result = block.nodelist.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/base.py" in render 
     823.     bit = self.render_node(node, context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/debug.py" in render_node 
     74.    return node.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/loader_tags.py" in render 
     62.    result = block.nodelist.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/base.py" in render 
     823.     bit = self.render_node(node, context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/debug.py" in render_node 
     74.    return node.render(context) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/template/debug.py" in render 
     87.    output = force_unicode(output) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/utils/encoding.py" in force_unicode 
     71.     s = unicode(s) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/forms/forms.py" in __unicode__ 
     411.   return self.as_widget() 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/forms/forms.py" in as_widget 
     458.   return widget.render(name, self.value(), attrs=attrs) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/forms/widgets.py" in render 
     547.   options = self.render_options(choices, [value]) 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/forms/widgets.py" in render_options 
     570.   for option_value, option_label in chain(self.choices, choices): 
    File "/Users/nb/Desktop/myenv2/lib/python2.7/site-packages/django/forms/models.py" in __iter__ 
     896.    for obj in self.queryset.all(): 

    Exception Type: AttributeError at /mymodels/add 
    Exception Value: 'function' object has no attribute 'all' 

Answer 1

好了，查詢集參數期待一個查詢集，而不是一個函數。

但功能是不必要的 - 你可以這樣做：

manufacturer = forms.ModelChoiceField(queryset=UniPart.objects.all().values('manufacturer').distinct()) 

應該做的正是你想要的。

Answer 2

queryset顯然並不需要一個調用。幸運的是，你不需要一個。只需構建一次查詢集並將其作爲queryset參數直接傳遞給ModelChoiceField即可。