Django: FieldError: 无法将关键字'name'解析为字段。可选项有: Name, id
我刚开始学习Django,正在跟着这个教程:Django教程第三部分:使用模型,在链接的步骤中遇到了这个问题。
- 我输入了命令:python3 manage.py makemigrations
- 接着又输入了:python3 manage.py migrate
在执行第二个命令后,出现了错误。
完整的错误信息是:
PS E:\DjangoDrill\locallibrary> python manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, catalog, contenttypes, sessions
Running migrations:
Applying catalog.0001_initial...Traceback (most recent call last):
File "manage.py", line 22, in <module>
main()
File "manage.py", line 18, in main
execute_from_command_line(sys.argv)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\core\management\__init__.py", line 442, in execute_from_command_line
utility.execute()
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\core\management\__init__.py", line 436, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\core\management\base.py", line 412, in run_from_argv
self.execute(*args, **cmd_options)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\core\management\base.py", line 458, in execute
output = self.handle(*args, **options)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\core\management\base.py", line 106, in wrapper
res = handle_func(*args, **kwargs)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\core\management\commands\migrate.py", line 356, in handle
post_migrate_state = executor.migrate(
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\migrations\executor.py", line 135, in migrate
state = self._migrate_all_forwards(
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\migrations\executor.py", line 167, in _migrate_all_forwards
state = self.apply_migration(
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\migrations\executor.py", line 252, in apply_migration
state = migration.apply(state, schema_editor)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\migrations\migration.py", line 132, in apply
operation.database_forwards(
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\migrations\operations\models.py", line 1135, in database_forwards
schema_editor.add_constraint(model, self.constraint)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\backends\sqlite3\schema.py", line 562, in add_constraint
super().add_constraint(model, constraint)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\backends\base\schema.py", line 532, in add_constraint
sql = constraint.create_sql(model, self)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\models\constraints.py", line 239, in create_sql
expressions = self._get_index_expressions(model, schema_editor)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\models\constraints.py", line 211, in _get_index_expressions
return ExpressionList(*index_expressions).resolve_expression(
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\models\expressions.py", line 950, in resolve_expression
c.source_expressions[pos] = arg.resolve_expression(
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\models\indexes.py", line 264, in resolve_expression
resolve_root_expression = root_expression.resolve_expression(
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\models\expressions.py", line 950, in resolve_expression
c.source_expressions[pos] = arg.resolve_expression(
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\models\expressions.py", line 829, in resolve_expression
return query.resolve_ref(self.name, allow_joins, reuse, summarize)
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\models\sql\query.py", line 1977, in resolve_ref
join_info = self.setup_joins(
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\models\sql\query.py", line 1824, in setup_joins
path, final_field, targets, rest = self.names_to_path(
File "C:\Users\Narea\AppData\Roaming\Python\Python38\site-packages\django\db\models\sql\query.py", line 1725, in names_to_path
raise FieldError(
django.core.exceptions.FieldError: Cannot resolve keyword 'name' into field. Choices are: Name, id
这是我的代码:
models.py文件内容:
from django.db import models
from django.urls import reverse
from django.db.models import UniqueConstraint
from django.db.models.functions import Lower
import uuid
class Genre(models.Model):
name = models.CharField(max_length=200, unique=True, help_text="Enter a book genre")
def get_absolute_url(self):
return reverse('genre-detail', args=[str(self.id)])
def __str__(self):
return self.name
class Meta:
constraints = [
UniqueConstraint(
Lower('name'),
name='genre_name_case_insensitive_unique',
violation_error_message = "Genre already exists (case insensitive match)"
),
]
class Book(models.Model):
title = models.CharField(max_length=200)
author = models.ForeignKey('Author', on_delete=models.RESTRICT, null=True)
summary = models.TextField(max_length=1000, help_text="Brief the story of the book")
isbn = models.CharField(max_length=13, unique=True, help_text='13 Character <a href="https://www.isbn-international.org/content/what-isbn''">ISBN number</a>')
genre = models.ManyToManyField(Genre, help_text="Genres for the book")
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('book-detail', args=[str(self.id)])
class BookInstance(models.Model):
id = models.UUIDField(primary_key=True, default= uuid.uuid4, help_text="Unique ID for this particular book across whole library")
book = models.ForeignKey('Book', on_delete=models.RESTRICT, null=True)
imprint = models.CharField(max_length=200)
due_back = models.DateField(null=True, blank=True)
LOAN_STATUS = (
('m', 'Maintenance'),
('o', 'On loan'),
('a', 'Available'),
('r', 'Reserved'),
)
status = models.CharField(
max_length=1,
choices=LOAN_STATUS,
blank=True,
default='m',
help_text='Book availability',
)
class Meta:
ordering = ['due_back']
def __str__(self):
return f'{self.id}({self.book.title})'
class Author(models.Model):
"""Model representing an author."""
first_name = models.CharField(max_length=100)
last_name = models.CharField(max_length=100)
date_of_birth = models.DateField(null=True, blank=True)
date_of_death = models.DateField('Died', null=True, blank=True)
class Meta:
ordering = ['last_name', 'first_name']
def get_absolute_url(self):
"""Returns the URL to access a particular author instance."""
return reverse('author-detail', args=[str(self.id)])
def __str__(self):
"""String for representing the Model object."""
return f'{self.last_name}, {self.first_name}'
admin.py文件内容:
from django.contrib import admin
from .models import Author, Genre, Book, BookInstance#, Language
admin.site.register(Book)
admin.site.register(Author)
admin.site.register(Genre)
admin.site.register(BookInstance)
# admin.site.register(Language)
catalog迁移0001_initial的内容:
# Generated by Django 4.2.11 on 2024-03-28 07:37
from django.db import migrations, models
import django.db.models.deletion
import django.db.models.functions.text
import uuid
class Migration(migrations.Migration):
initial = True
dependencies = [
]
operations = [
migrations.CreateModel(
name='Author',
fields=[
('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('first_name', models.CharField(max_length=100)),
('last_name', models.CharField(max_length=100)),
('date_of_birth', models.DateField(blank=True, null=True)),
('date_of_death', models.DateField(blank=True, null=True, verbose_name='Died')),
],
options={
'ordering': ['last_name', 'first_name'],
},
),
migrations.CreateModel(
name='Book',
fields=[
('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('title', models.CharField(max_length=200)),
('summary', models.TextField(help_text='Brief the story of the book', max_length=1000)),
('isbn', models.CharField(help_text='13 Character <a href="https://www.isbn-international.org/content/what-isbn">ISBN number</a>', max_length=13, unique=True)),
],
),
migrations.CreateModel(
name='BookInstance',
fields=[
('id', models.UUIDField(default=uuid.uuid4, help_text='Unique ID for this particular book across whole library', primary_key=True, serialize=False)),
('imprint', models.CharField(max_length=200)),
('due_back', models.DateField(blank=True, null=True)),
('status', models.CharField(blank=True, choices=[('m', 'Maintenance'), ('o', 'On loan'), ('a', 'Available'), ('r', 'Reserved')], default='m', help_text='Book availability', max_length=1)),
],
options={
'ordering': ['due_back'],
},
),
migrations.CreateModel(
name='Genre',
fields=[
('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('Name', models.CharField(help_text='Enter a book genre', max_length=200, unique=True)),
],
),
migrations.AddConstraint(
model_name='genre',
constraint=models.UniqueConstraint(django.db.models.functions.text.Lower('name'), name='genre_name_case_insensitive_unique', violation_error_message='Genre already exists'),
),
migrations.AddField(
model_name='bookinstance',
name='book',
field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.RESTRICT, to='catalog.book'),
),
migrations.AddField(
model_name='book',
name='author',
field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.RESTRICT, to='catalog.author'),
),
migrations.AddField(
model_name='book',
name='genre',
field=models.ManyToManyField(help_text='Genres for the book', to='catalog.genre'),
),
]
我查找了一些类似的问题,但没有找到和我的问题很相关的解决方案。
1 个回答
0
目前在模型 Genre
中没有 Name
这个字段,但有一个 name
字段。catalog migration 0001_initial
表明这并不是一直如此,某个时候这个情况发生了变化。
migrations.CreateModel(
name='Genre',
fields=[
('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('Name', models.CharField(help_text='Enter a book genre', max_length=200, unique=True)),
], ^
), |- - Added initially
最简单的解决办法就是直接把数据库删掉,然后重新开始。当然,这样做不太专业,但如果没有什么值得保留的东西,那就没必要给自己增加压力了。
其实有很多解决方案,我会尝试一些,然后再回来分享测试结果。