Django内联表单和选项字段会生成太多的数据库查询 [英] Django inline formsets and choicefields generate too many db queries

问题描述

我有一个具有多个外键字段的模型，例如模型产品具有字段类型，级别，颜色，强度（仅仅是一般示例）。

然后我有一个页面来编辑所有产品一种给定类型的类型，使用产品作为一个内联格式集，并可以使用 extra = 10 添加其他产品的选项。

我发现非常奇怪的是，每次当我输出模板上的一个外键选择字段Django查询数据库获取选项（每次）。

例如：

  {％for form in formset％} 
 {{form .level}} 
 {{form.color}} 
 {{form.intensity}} 
 {％endfor％} 
  

有20个产品（和10个空的额外表单）上述代码问题30 select ... from ... ，颜色和强度共有90个查询（使用Django Debug Toolbar显示），其中3应该是足够的。这些选项不太可能改变中间请求，但即使他们确实不希望一些新添加的选项仅在最后的5个表单中出现。

有没有办法优化我的模型/表单/视图/模板，以便数据库不会像这样不必要的锤击？

-

免责声明：我对django和python来说比较新，不禁想到必须有办法以某种方式解决这个问题。 / p>

解决方案

  field_queryset = Test.objects.all（）
表单中的表单：
 form.fields ['test_field']。queryset = field_queryset 
  

/ p>

I have a model with a number of foreign key fields, e.g. model Product with fields 'type', 'level', 'color', 'intensity' (just a generic example).

I then have a page to edit all products of a given type using a Type form with the products as an inline formset with the option to add additional products inline using extra=10.

The thing i find very strange is that each time when i output one of the foreign key choice fields on the template Django queries the database for the get the options (every time).

For example:

{% for form in formset %}
    {{ form.level }}
    {{ form.color }}
    {{ form.intensity }}
{% endfor %}

With 20 products (and 10 empty extra forms) the above code issues 30 select * from ... from level, color and intensity totaling 90 queries (revealed using the Django Debug Toolbar), where 3 should be sufficient. The options are unlikely to change mid request, but even if they did I definitely wouldn't want some newly added options to appear in the last 5 forms only.

Is there any way to optimize my models/forms/views/templates so that the database doesn't get hammered like this unnecessarily?

-

Disclaimer: I'm relatively new to django and python and can't help thinking there must be a way to address this built in somehow.

解决方案

field_queryset = Test.objects.all()    
for form in formset:
        form.fields['test_field'].queryset = field_queryset

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