Question

我不明白django-import-export模块如何处理ForeignKeys。这是一个简单的例子： models.py

class TFamilies(models.Model):
    id_fam = models.AutoField(primary_key=True, unique=True)
    name_fam = models.CharField(max_length=1024, blank=True,verbose_name='Famille')


class TGenus(models.Model):
    id_genus = models.AutoField(primary_key=True, unique=True)
    name_genus = models.CharField(max_length=1024,verbose_name='nom de genre')
    id_fam = models.ForeignKey(TFamilies, null=True, db_column='id_fam', blank=True, verbose_name='Famille')

我想允许人们添加与家庭相关的属！只有name_genus和name_fam的CSV / XLS ...（并且id留空）。

大多数时候家庭已经存在于DB中，Django juste必须找到正确的id号...

admin.py

class TGenusResource(resources.ModelResource):

    name_fam = fields.Field(widget=widgets.ForeignKeyWidget(TFamilies, 'name_fam'))

    class Meta:
        model = TGenus
        import_id_fields = ['id_genus']


class TGenusAdmin(ImportExportActionModelAdmin):
    form = TGenusAdminForm
    resource_class = TGenusResource
    pass

此配置导致导入界面出错：

Line number: 1 - 'NoneType' object has no attribute 'name_fam'
Traceback (most recent call last):
File "/....../lib/python2.7/site-packages/import_export/resources.py", line 348, in import_data
row_result.object_repr = force_text(instance)
File "......./lib/python2.7/site-packages/django/utils/encoding.py", line 85, in force_text
s = six.text_type(s)
AttributeError: 'NoneType' object has no attribute 'name_fam'

我不明白...... 我也尝试过回答：django-import-export resource definition for foreignkey field? 有点像：Foreign Key in django migration using django-import-export

我是否必须使用before_import来找到自己的比赛？

Answer 1

我发现你必须找到自己的比赛！在Tablib数据集中更改值是不可能的，因此您必须记录条目进行更改并将它们放回到新行中然后删除旧行。

我的Excel模板包含由家庭名称填充的列id_genus（空），name_genus和id_fam！

对于任何降落在这里的人，我都会发布：

def before_import(self, dataset, dry_run):
        """
        Make standard corrections to the dataset before displaying to user
        """

        i = 0
        last = dataset.height - 1

        # for all lines, search for id of family given and add a new line at the bottom with it then delete the first one
        while i <= last:
            # Check if the Genus exist in DB
            if (TGenus.objects.filter(name_genus=dataset.get_col(2)[0].capitalize())):
                id_genus = TGenus.objects.filter(name_genus=dataset.get_col(2)[0].capitalize())[0].id_genus
            else :
                id_genus = ''
            # Check if the family exists in DB
            try:
                TFamilies.objects.get(name_fam=dataset.get_col(2)[0].capitalize())
            except TFamilies.DoesNotExist:
                raise Exception("Family not in DB !")                   
            except TFamilies.MultipleObjectsReturned:
                pass

            # use of "filter" instead of "get" to prevent duplicate values, select the first one in all cases
            dataset.rpush((id_genus,
                dataset.get_col(1)[0],
                TFamilies.objects.filter(name_fam=dataset.get_col(2)[0].capitalize())[0].id_fam))
            dataset.lpop()
            i = i + 1

我的django管理员可以被非sys-admin使用，因此，他们可以复制不属于DB的属或家庭... 如果有人想要更好地处理错误，我想阅读它！此外，我想在预览中保留家庭的名字，不仅仅是她的身份......如果您知道如何，我已经发布了另一个问题：Is-it possible to customize the template of preview in django import-export?

Answer 2

我认为您需要根据模型 TGenus 中的字段名称重命名：

  id_fam = fields.Field(widget=widgets.ForeignKeyWidget(TFamilies, 'name_fam')) 
instead of:
  name_fam = fields.Field(widget=widgets.ForeignKeyWidget(TFamilies, 'name_fam'))

处理django-import-export中的外键导入

2 个答案: