将AND和OR与Q对象组合在一起的Django查询过滤器不会返回预期的结果 [英] Django query filter combining AND and OR with Q objects don't return the expected results

问题描述

我尝试在使用Q对象的过滤器中结合AND和OR。它看起来像那个|表现得像AND一样。这与之前的批注相关，而该注释在同一查询中运行，而不是子查询。

I try to combine AND and OR in a filter using Q objects. It looks like that the | behave like an AND. This is related to the previous annotate which is run in the same query and not as a subquery.

使用Django处理此方法的正确方法是什么？

What is the correct way to handle this with Django?

models.py

class Type(models.Model):
    name = models.CharField(_('name'), max_length=100)
    stock = models.BooleanField(_('in stock'), default=True)
    hide = models.BooleanField(_('hide'), default=False)
    deleted = models.BooleanField(_('deleted'), default=False)

class Item(models.Model):
    barcode = models.CharField(_('barcode'), max_length=100, blank=True)
    quantity = models.IntegerField(_('quantity'), default=1)
    type = models.ForeignKey('Type', related_name='items', verbose_name=_('type'))

views.py

def hire(request):
    categories_list = Category.objects.all().order_by('sorting')
    types_list = Type.objects.annotate(quantity=Sum('items__quantity')).filter(
        Q(hide=False) & Q(deleted=False),
        Q(stock=False) | Q(quantity__gte=1))
    return render_to_response('equipment/hire.html', {
           'categories_list': categories_list,
           'types_list': types_list,
           }, context_instance=RequestContext(request))

生成的SQL查询

SELECT "equipment_type"."id" [...] FROM "equipment_type" LEFT OUTER JOIN
    "equipment_subcategory" ON ("equipment_type"."subcategory_id" =
    "equipment_subcategory"."id") LEFT OUTER JOIN "equipment_item" ON
    ("equipment_type"."id" = "equipment_item"."type_id") WHERE 
    ("equipment_type"."hide" = False AND "equipment_type"."deleted" = False )
    AND ("equipment_type"."stock" = False )) GROUP BY "equipment_type"."id"
    [...] HAVING SUM("equipment_item"."quantity") >= 1

预期的SQL查询

SELECT
    *
FROM
    equipment_type
LEFT JOIN (
    SELECT type_id, SUM(quantity) AS qty
    FROM equipment_item
    GROUP BY type_id
) T1
ON id = T1.type_id
WHERE hide=0 AND deleted=0 AND (T1.qty > 0 OR stock=0)

---

编辑：我添加了预期的SQL查询（没有在device_subcategory上加入）

---

EDIT: I added the expected SQL query (without the join on equipment_subcategory)

推荐答案

#django。所以，我选择使用原始的SQL查询来解决这个问题...

OK, no success here or on #django. So I choose to use a raw SQL query to solve this problem...

下面的工作代码：

types_list = Type.objects.raw('SELECT * FROM equipment_type
    LEFT JOIN (                                            
        SELECT type_id, SUM(quantity) AS qty               
        FROM equipment_item                                
        GROUP BY type_id                                   
    ) T1                                                   
    ON id = T1.type_id                                     
    WHERE hide=0 AND deleted=0 AND (T1.qty > 0 OR stock=0) 
    ')

这篇关于将AND和OR与Q对象组合在一起的Django查询过滤器不会返回预期的结果的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！