Question

您好我的views.py

中有以下查询

<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:context="http://www.springframework.org/schema/context"
 xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">

给出值m = Request.objects.filter(Q(type__icontains='4'), Q(wt__in =['giga','mega'])) context['all_items'] = m.values('type1').order_by('type1')

如何在这种情况下实现Django Substr，以便我的html将值显示为sasoo, masoo, pisoo, kusoo etc.

Answer 1

您可以annotate模型

from django.db.models.functions import Substr
m = Request.objects.filter(Q(type__icontains='4'), Q(wt__in =['giga','mega']))
context['all_items'] = m.annotate(mysubstring=Substr('type1',1,2)).order_by('type1')

在模板中：

{% for obj in all_items %}
    {# Use obj.mysubstring #}
{% endfor %}

Answer 2

您可以在模板中使用slice过滤器：

{% for item in all_items %}
  {{ item.type1|slice:":2" }}
{% endfor %}

Answer 3

一个班轮

context['all_items'] = [i[:2] for i in context['all_items']]

如何获得值的Substr

3 个答案: