我有一个django博客项目，其中包含以下核心模型：
Models.py
class Category(models.Model):
parentCategoryName = models.ForeignKey('self', blank=True,
null=True)
parentCatSlug = models.SlugField(null=True, blank=True)
categoryName = models.CharField(max_length=200, null=True)
categorySlug = models.SlugField(null=True, blank=True)
def __str__(self):
full_path = [self.categoryName]
k = self.parentCategoryName
while k is not None:
full_path.append(k.categoryName)
k = k.parentCategoryName
return ' -> '.join(full_path[::-1])
class Meta:
verbose_name_plural = "categories"
def save(self, *args, **kwargs):
self.categorySlug = slugify(self.categoryName)
self.parentCatSlug = slugify(self.parentCategoryName)
super(Category, self).save(*args, **kwargs)
class Post(models.Model):
title = models.CharField(max_length=200)
category = models.ForeignKey('Category', null=True, blank=True)
summary = models.CharField(max_length=500, default=True)
body = RichTextUploadingField()
pub_date = models.DateTimeField(default=timezone.now)
author = models.ForeignKey(User, default=True)
titleSlug = models.SlugField(blank=True)
authorSlug = models.SlugField(blank=True)
editedimage = ProcessedImageField(upload_to="primary_images",
null=True,
processors = [Transpose()],
format="JPEG")
show_in_posts = models.BooleanField(default=True)
def save(self, *args, **kwargs):
self.titleSlug = slugify(self.title)
self.authorSlug = slugify(self.author)
super(Post, self).save(*args, **kwargs)
def __str__(self):
return self.title
当我运行makemigrations并进行迁移时，一切都工作正常，但过了一会儿，我得到上面的错误。我之前已经发布了一个问题，解决方案是删除数据库并重新创建它。这仍然有效，但它经常发生，所以我不得不放弃并重新创建。任何人都可以帮助解释为什么这似乎偶尔会发生吗？
回溯
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/db/backends/utils.py" in execute
65. return self.cursor.execute(sql, params)
The above exception (column posts_post.category_id does not exist
LINE 1: SELECT "posts_post"."id", "posts_post"."title", "posts_post"...
^
) was the direct cause of the following exception:
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/core/handlers/exception.py" in inner
41. response = get_response(request)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
187. response = self.process_exception_by_middleware(e, request)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/core/handlers/base.py" in _get_response
185. response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/Users/davidmellor/code/nomadpad/posts/views.py" in getPosts
27. return render(request, 'posts/getPosts.html', context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/shortcuts.py" in render
30. content = loader.render_to_string(template_name, context, request, using=using)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/loader.py" in render_to_string
68. return template.render(context, request)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/backends/django.py" in render
66. return self.template.render(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/base.py" in render
207. return self._render(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/base.py" in _render
199. return self.nodelist.render(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/base.py" in render
990. bit = node.render_annotated(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/base.py" in render_annotated
957. return self.render(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/loader_tags.py" in render
177. return compiled_parent._render(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/base.py" in _render
199. return self.nodelist.render(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/base.py" in render
990. bit = node.render_annotated(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/base.py" in render_annotated
957. return self.render(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/loader_tags.py" in render
72. result = block.nodelist.render(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/base.py" in render
990. bit = node.render_annotated(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/base.py" in render_annotated
957. return self.render(context)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/template/defaulttags.py" in render
321. if match:
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/db/models/query.py" in __bool__
254. self._fetch_all()
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/db/models/query.py" in _fetch_all
1118. self._result_cache = list(self._iterable_class(self))
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/db/models/query.py" in __iter__
53. results = compiler.execute_sql(chunked_fetch=self.chunked_fetch)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/db/models/sql/compiler.py" in execute_sql
894. raise original_exception
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/db/models/sql/compiler.py" in execute_sql
884. cursor.execute(sql, params)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/db/backends/utils.py" in execute
80. return super(CursorDebugWrapper, self).execute(sql, params)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/db/backends/utils.py" in execute
65. return self.cursor.execute(sql, params)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/db/utils.py" in __exit__
94. six.reraise(dj_exc_type, dj_exc_value, traceback)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/utils/six.py" in reraise
685. raise value.with_traceback(tb)
File "/Users/davidmellor/anaconda/envs/py3/lib/python3.6/site-packages/django/db/backends/utils.py" in execute
65. return self.cursor.execute(sql, params)
Exception Type: ProgrammingError at /
Exception Value: column posts_post.category_id does not exist
LINE 1: SELECT "posts_post"."id", "posts_post"."title", "posts_post"...
^
迁移
from __future__ import unicode_literals
import ckeditor_uploader.fields
from django.conf import settings
from django.db import migrations, models
import django.db.models.deletion
import django.utils.timezone
import imagekit.models.fields
class Migration(migrations.Migration):
initial = True
dependencies = [
migrations.swappable_dependency(settings.AUTH_USER_MODEL),
]
operations = [
migrations.CreateModel(
name='Category',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('parentCatSlug', models.SlugField(blank=True, null=True)),
('categoryName', models.CharField(max_length=200, null=True)),
('categorySlug', models.SlugField(blank=True, null=True)),
('parentCategoryName', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='posts.Category')),
],
options={
'verbose_name_plural': 'categories',
},
),
migrations.CreateModel(
name='Comment',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('title', models.CharField(max_length=200)),
('pub_date', models.DateTimeField(default=django.utils.timezone.now)),
('body', models.CharField(max_length=200)),
('approved_comment', models.BooleanField(default=True)),
('author', models.ForeignKey(default=True, on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
],
),
migrations.CreateModel(
name='Post',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('title', models.CharField(max_length=200)),
('summary', models.CharField(default=True, max_length=500)),
('body', ckeditor_uploader.fields.RichTextUploadingField()),
('pub_date', models.DateTimeField(default=django.utils.timezone.now)),
('titleSlug', models.SlugField(blank=True)),
('authorSlug', models.SlugField(blank=True)),
('editedimage', imagekit.models.fields.ProcessedImageField(null=True, upload_to='primary_images')),
('show_in_posts', models.BooleanField(default=True)),
('author', models.ForeignKey(default=True, on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
('category', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='posts.Category')),
],
),
migrations.CreateModel(
name='Profile',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('bio', models.TextField(blank=True, max_length=500)),
('location', models.CharField(blank=True, max_length=30)),
('birth_date', models.DateField(blank=True, null=True)),
('slug', models.SlugField(default='', unique=True)),
('profile_picture', models.ImageField(blank=True, upload_to='profile_images')),
('user', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
],
),
migrations.AddField(
model_name='comment',
name='post',
field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='posts.Post'),
),
]
答案 0 :(得分：1)
当我删除我的迁移文件时，我进入了我的mac的文件结构，并清除了所有pycache文件，这些文件不会显示在我的文本编辑器中。虽然我对原因的理解不清楚，但这很有效。
答案 1 :(得分：0)
嗯，从我所看到的情况来看，它看起来不像你的Post模型有category_id字段。我必须看到更多的代码才能理解为什么有一个SQL查询试图在该字段上进行选择。
您是否可以共享产生错误的数据库调用？