Python ValueError：字段'；id'；应为一个数字，但得到'；选择'；

运行“python manage.py migrate”命令时出错：

要执行的操作： 应用所有迁移：管理、身份验证、内容类型、会话、travello 运行迁移： 正在应用travello.0005_auto_20200313_1046…回溯（最近一次呼叫最后一次）： 文件“C:\Users\uc\Envs\test\lib\site packages\django\db\models\fields\u_init\u_.py”，第1772行，在get\u prep\u值中 返回int（值） ValueError:基数为10的int（）的文本无效：“选择”

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "manage.py", line 21, in <module>
    main()
  File "manage.py", line 17, in main
    execute_from_command_line(sys.argv)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\core\management\__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "C:\Users\uc\Envs\test\lib\site-packages\django\core\management\__init__.py", line 395, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\core\management\base.py", line 328, in run_from_argv
    self.execute(*args, **cmd_options)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\core\management\base.py", line 369, in execute
    output = self.handle(*args, **options)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\core\management\base.py", line 83, in wrapped
    res = handle_func(*args, **kwargs)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\core\management\commands\migrate.py", line 231, in handle
    post_migrate_state = executor.migrate(
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\migrations\executor.py", line 117, in migrate
    state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\migrations\executor.py", line 147, in _migrate_all_forwards
    state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\migrations\executor.py", line 245, in apply_migration
    state = migration.apply(state, schema_editor)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\migrations\migration.py", line 124, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\migrations\operations\fields.py", line 249, in database_forwards
    schema_editor.alter_field(from_model, from_field, to_field)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\backends\base\schema.py", line 564, in alter_field
    self._alter_field(model, old_field, new_field, old_type, new_type,
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\backends\postgresql\schema.py", line 152, in _alter_field
    super()._alter_field(
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\backends\base\schema.py", line 679, in _alter_field
    new_default = self.effective_default(new_field)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\backends\base\schema.py", line 303, in effective_default
    return field.get_db_prep_save(self._effective_default(field), self.connection)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\models\fields\related.py", line 939, in get_db_prep_save
    return self.target_field.get_db_prep_save(value, connection=connection)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\models\fields\__init__.py", line 821, in get_db_prep_save
    return self.get_db_prep_value(value, connection=connection, prepared=False)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\models\fields\__init__.py", line 2365, in get_db_prep_value
    value = self.get_prep_value(value)
  File "C:\Users\uc\Envs\test\lib\site-packages\django\db\models\fields\__init__.py", line 1774, in get_prep_value
    raise e.__class__(
ValueError: Field 'id' expected a number but got 'select'.

admin.py

 from django.db import models

class Destination(models.Model):  
    name = models.CharField(max_length=200)
    desc = models.TextField()
    price = models.IntegerField()
    img = models.ImageField(upload_to= 'pics')
    offer = models.BooleanField(default=False)

class Category(models.Model):
    cat_name = models.CharField(max_length = 50)

    def __str__(self):
        return self.cat_name

class Blog(models.Model):
    date = models.DateField()
    name = models.CharField(max_length=100)
    category = models.ForeignKey(Category, on_delete=models.CASCADE, default=0)
    desc = models.TextField()
    img = models.ImageField(upload_to= 'blog_img')

class Subscribe(models.Model):
    name = models.CharField(max_length=100)
    email = models.CharField(max_length=100)

from django.contrib import admin
from .models import Destination
from .models import Blog
from .models import Category
from .models import Subscribtion
admin.autodiscover()

admin.site.register(Destination)
admin.site.register(Blog)
admin.site.register(Category)
admin.site.register(Subscribtion)

from django.db import migrations, models
import django.db.models.deletion
import django.utils.timezone


class Migration(migrations.Migration):

    dependencies = [
        ('travello', '0004_auto_20200312_1224'),
    ]

    operations = [
        migrations.RemoveField(
            model_name='blog',
            name='date',
        ),
        migrations.AddField(
            model_name='blog',
            name='created_at',
            field=models.DateTimeField(auto_now_add=True, default=django.utils.timezone.now),
            preserve_default=False,
        ),
        migrations.AddField(
            model_name='blog',
            name='updated_at',
            field=models.DateTimeField(auto_now=True),
        ),
        migrations.AlterField(
            model_name='blog',
            name='category',
            field=models.ForeignKey(default='select', on_delete=django.db.models.deletion.CASCADE, to='travello.Category'),
        ),
    ]

0005_auto_20200313_1046.py

 from django.db import models

class Destination(models.Model):  
    name = models.CharField(max_length=200)
    desc = models.TextField()
    price = models.IntegerField()
    img = models.ImageField(upload_to= 'pics')
    offer = models.BooleanField(default=False)

class Category(models.Model):
    cat_name = models.CharField(max_length = 50)

    def __str__(self):
        return self.cat_name

class Blog(models.Model):
    date = models.DateField()
    name = models.CharField(max_length=100)
    category = models.ForeignKey(Category, on_delete=models.CASCADE, default=0)
    desc = models.TextField()
    img = models.ImageField(upload_to= 'blog_img')

class Subscribe(models.Model):
    name = models.CharField(max_length=100)
    email = models.CharField(max_length=100)

from django.contrib import admin
from .models import Destination
from .models import Blog
from .models import Category
from .models import Subscribtion
admin.autodiscover()

admin.site.register(Destination)
admin.site.register(Blog)
admin.site.register(Category)
admin.site.register(Subscribtion)

from django.db import migrations, models
import django.db.models.deletion
import django.utils.timezone


class Migration(migrations.Migration):

    dependencies = [
        ('travello', '0004_auto_20200312_1224'),
    ]

    operations = [
        migrations.RemoveField(
            model_name='blog',
            name='date',
        ),
        migrations.AddField(
            model_name='blog',
            name='created_at',
            field=models.DateTimeField(auto_now_add=True, default=django.utils.timezone.now),
            preserve_default=False,
        ),
        migrations.AddField(
            model_name='blog',
            name='updated_at',
            field=models.DateTimeField(auto_now=True),
        ),
        migrations.AlterField(
            model_name='blog',
            name='category',
            field=models.ForeignKey(default='select', on_delete=django.db.models.deletion.CASCADE, to='travello.Category'),
        ),
    ]

---

您可以共享

0005_auto_20200313_1046.py

迁移文件吗？请检查上载“0005_auto_20200313_1046.py”代码是否可以更改

字段=models.ForeignKey（默认值为
字段=models.ForeignKey（默认值为0
在迁移文件中并运行迁移命令检查是否有效，然后通知我出现此错误的“TypeError:预期字符串或类似字节的对象”不起作用使用这两个命令您可以共享迁移文件吗？请检查上载“0005\u auto\u 20200313\u 1046.py”代码是否可以将
字段=models.ForeignKey（默认值为选择“
更改为
字段=models.ForeignKey（默认值=0
在您的迁移文件中，运行migrate命令检查是否正常，然后告诉我发生此错误的“TypeError:预期字符串或类似字节的对象”不正常使用这两个命令