Question

使用Django 1.7：

我的Queryset看起来像这样：

    return super(EmployeeViewSet, self).get_queryset()\
           .filter(status__deleted_flag=False, **filter_kwargs)\
           .prefetch_related('phone_number_set', 'email_address_set', 'street_address_set',
                             Prefetch('file_set', EmployeeFile.objects.active().select_related('content_type')))\
           .order_by('last_name', 'first_name')

DjDT显示执行的预取查询

SELECT ••• FROM "employees_employeefile" INNER JOIN "employees_employeefiletype" 
ON ("employees_employeefile"."content_type_id" = "employees_employeefiletype"."id" )
WHERE ("employees_employeefile"."deleted_at" IS NULL 
       AND "employees_employeefile"."owner_id" IN (53, 81, ...)) 
ORDER BY "employees_employeefile"."created_at" DESC

然后，DjDT显示每个员工被重新获得相同的文件列表

SELECT ••• FROM "employees_employeefile" 
WHERE ("employees_employeefile"."owner_id" = 53 
       AND "employees_employeefile"."deleted_at" IS NULL) 
ORDER BY "employees_employeefile"."created_at" DESC

他们的查询看起来和我一样，用于执行选择的ModelManager方法与(EmployeeFile.objects.active()) vs employee.file_set.active()

相同

另外，我尝试删除select_related('content_type')以防万一是问题

为什么在prefetch_related中忽略Prefetch对象？

0 个答案: