筛选/限制Django order_by [英] filter/limit django order_by
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问题描述
使用django ORM,有没有办法限制或过滤order_by适用的范围?
Using the django ORM, Is there a way to limit or filter the scope of what order_by applies to?
Product.objects.filter(
product_type__name=choices.PRODUCT_BOOK
).order_by(
# need to order these last names by those
# who have a role code of "A01", then "B01"
'contributor__writer__last_name'
)
推荐答案
即使使用原始SQL,也无法仅对某些行应用订单。因此,最好的方法是将alls排序并按role_code分组。
Even using raw SQL is not possible to apply an order by just to some rows. So the best way, order alls and group by role_code.
您还可以使用 role_code
A01
或 B01
,对其进行订购,然后获取其余贡献者(如果 role_code
) > A01 或 B01
。然后合并查询结果。
Also you can get contributors with role_code
"A01"
or "B01"
, order them, then get the rest contributors excluding their role_code
if is "A01"
or "B01"
. Then merge query results.
order_products = Product.objects.filter(
product_type__name=choices.PRODUCT_BOOK
).filter(contributor__role_code__in=['A01','B01'])
.order_by(
# need to order these last names by those
# who have a role code of "A01", then "B01"
'contributor__writer__last_name'
)
non_order_products = Product.objects.filter(
product_type__name=choices.PRODUCT_BOOK
).exclude(contributor__role_code__in=['A01','B01'])
final_result = order_products | non_order_products
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