我有三种模式，艺术家，场地和活动。事件模型链接到艺术家和地点。当使用django-import-export导入事件数据时，我希望能够使用Artist或Venue名称而不是主键进行添加。
到目前为止，只有在尚未创建导入模型的情况下，我才设法使它生效。
。我的代码如下：
admin.py
from django.contrib import admin
from django import forms
from .models import Venue, Artist, Event
from import_export.admin import ImportExportModelAdmin
from import_export import fields, resources
from import_export.widgets import ForeignKeyWidget
class ArtistForeignKeyWidget(ForeignKeyWidget):
def clean(self, value,row=None,*args, **kwargs):
#this takes the value of the input and passes it to 'get_or_create'
artist, created = Artist.objects.get_or_create(artist_name=value)
#if the artist already exist
#this returns a UNIQUE constraint error, needs fixing
if created == False:
return artist
#if the artist has been created (works fine)
else:
return artist
class VenueForeignKeyWidget(ForeignKeyWidget):
def clean(self, value,row=None,*args, **kwargs):
venue, created = Venue.objects.get_or_create(venue_name=value)
if created == False:
return venue
else:
#return new venue element
return venue
class EventResource(resources.ModelResource):
#create ForeignKeyWidget to replace Artist & VEnue primary key with name in import/export
artist = fields.Field(column_name='artist', attribute='artist', widget=ArtistForeignKeyWidget(Artist, 'artist_name'))
venue = fields.Field(column_name='venue', attribute='venue', widget=VenueForeignKeyWidget(Venue, 'venue_name'))
class Meta:
model = Event
exclude = ('user', 'updated')
fields = (
'id',
'date',
'time',
'event_code',
'system',
'CAM',
'age_restrictions',
'entry_restrictions',
)
class ArtistAdmin(ImportExportModelAdmin):
actions = None
list_display = ["artist_name", "genre"]
list_filter = ["genre"]
search_fields = ["artist_name", "genre"]
class EventAdmin(ImportExportModelAdmin):
actions = None
resource_class = EventResource
list_display = ["date", "artist", "venue", "event_code", "CAM"]
list_filter = ["date", "CAM"]
search_fields = ["date", "artist__artist_name", "venue__venue_name", "event_code", "CAM", "system"]
class VenueAdmin(ImportExportModelAdmin):
actions = None
list_display = ["venue_name", "venue_city", "address", "loa", "system_venue"]
list_filter = ["venue_city", "loa", "system_venue"]
search_fields = ["venue_name", "venue_city"]
admin.site.register(Venue, VenueAdmin)
admin.site.register(Artist, ArtistAdmin)
admin.site.register(Event, EventAdmin)
我无法理解为什么返回已经创建的艺术家会返回UNIQUE约束错误，而不是仅仅接受已经创建的对象。谁能帮忙解释一下，以便我更正我的代码？