我try 使用Q对象在过滤中组合AND和OR.看起来|他们的行为就像一个AND.这与前面的注释相关,该注释在同一查询中运行,而不是作为子查询运行.
用Django处理这个问题的正确方法是什么?
models.py个
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个
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))
resulting SQL query
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
expected SQL query个
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)
EDIT:我添加了预期的SQL查询(在Equipment_Subategory上没有连接)