如何解决Django中与外键有关的DeleteView问题? [英] How can solve a DeleteView problem in Django concerning a foreign key?

问题描述

我必须使用应用程序(DMS和ObjPDW).第一个是用于管理某些文件.在这里，我有一个模型DMS_Dokument，其中包括FileField等.最近，我在后一个应用程序(ObjPDW)中添加了新模型，并在Dokument_DMS中添加了外键:

  Zahlungsstrom类(models.Model):zahlung_bezeichnung = models.CharField(max_length = 550，blank = False，null = False，verbose_name ="Bezeichnung")zahlung_betrag = models.DecimalField(max_digits = 7，decimal_places = 2，default = None，blank = True，null = True)zahlung_dok_fk =模型.ForeignKey(dmsdok.DMS_Dokument，on_delete =模型.SET_DEFAULT，默认值=无，null =真，空白=真，verbose_name ="Zahlungsdokument") 

现在我想删除DMS_Dokument对象(使用DeleteView CBV)，但是它给了我一个"prorammingerror":(1146，表'DB_DMS.ObjPDW_zahlungsstrom'不存在"))/p>

我不知道问题是什么.:(

只是为了清楚起见.这两个应用程序都有自己的数据库.我知道Django不建议在两个数据库之间建立模型关联，但是由于我不是一位经验丰富的程序员，所以我不知道为什么我可以使这种关系起作用，但是删除是一个问题.

此外，我想在此处包括更多有关DMS_Dokument模型的代码.它还具有删除定义.

  class DMS_Dokument(models.Model):dms_dok_titel = models.CharField(max_length = 255，blank = True)dms_dok_beschreibung = models.CharField(max_length = 3000，blank = True，null = True)dms_dok_datei = models.FileField(max_length = 255，upload_to ='DMS/')dms_dok_gehoert_zu_app = models.CharField(max_length = 255，choices = app_choices，blank = False，null = False)def save(self，* args，** kwargs):reserve_ext =扩展名(self.dms_dok_datei.name)neuer_dateiname = self.dms_dok_gehoert_zu_app +'_'+ self.dms_dok_titel +'_'+ self.dms_dok_hochgeladen_am.strftime(％d.％m.％Y")self.dms_dok_datei.name = neuer_dateiname + prepare_ext超级(DMS_Dokument，self).save(* args，** kwargs)def delete(self):self.indexes.all().delete()超级(DMS_Dokument，self).delete() 

也许有帮助.

解决方案

该错误表明该表不存在.您必须发出以下命令来创建迁移并在数据库中创建表:

  python manage.py makemigrationspython manage.py迁移 

I have to apps (DMS and ObjPDW). The first one is for managing some files. In this I have a model DMS_Dokument, which includes a FileField and some more. Recently I added a new model to the latter app (ObjPDW) and I included a foreign key to Dokument_DMS:

class Zahlungsstrom(models.Model):
    zahlung_bezeichnung = models.CharField(max_length=550, blank=False, null=False, verbose_name="Bezeichnung")
    zahlung_betrag = models.DecimalField(max_digits=7, decimal_places=2, default=None, blank=True, null=True)
      zahlung_dok_fk = models.ForeignKey(dmsdok.DMS_Dokument, on_delete=models.SET_DEFAULT, default=None, null=True, blank=True, verbose_name="Zahlungsdokument")

Now I wanted to delete a DMS_Dokument object (using the DeleteView CBV), but it gives me a "prorammingerror": "(1146, "Table 'DB_DMS.ObjPDW_zahlungsstrom' doesn't exist")"

I have no clue what the problem is. :(

Edit: Just to be clear on this. Both apps have their own databases. I know that Django is not recommending to relate models between two databases, but as I am no experienced programmer I do not know why I can make the relations work, but deletion is such a problem.

Furthermore I want to include some more code here, which is about the DMS_Dokument model. It also has a delete def.

class DMS_Dokument(models.Model):
    dms_dok_titel = models.CharField(max_length=255, blank=True)
    dms_dok_beschreibung = models.CharField(max_length=3000, blank=True, null=True)
    dms_dok_datei = models.FileField(max_length=255,upload_to='DMS/')
    dms_dok_gehoert_zu_app = models.CharField(max_length=255, choices=app_choices, blank=False, null=False)

    def save(self, *args, **kwargs):
        preserve_ext = extension(self.dms_dok_datei.name)
        neuer_dateiname = self.dms_dok_gehoert_zu_app + '_' + self.dms_dok_titel + '_' + self.dms_dok_hochgeladen_am.strftime("%d.%m.%Y")
        self.dms_dok_datei.name = neuer_dateiname + preserve_ext
        super(DMS_Dokument, self).save(*args, **kwargs)

    def delete(self):
        self.indexes.all().delete()
        super(DMS_Dokument, self).delete()

Perhaps this helps.

解决方案

The error says the table does not exist. You must issue the following commands to create the migrations and make the table in you DB:

python manage.py makemigrations
python manage.py migrate

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