我在我的博客上工作，但是当我迁移它时给了我一个错误：“期望的字符串或缓冲区”错误。在第22行。它是一个收集视图时间的整体模型，我想可能是在view.py中更改了值，并且在创建模型后可能无法修改模型。
所以我尝试chage default并在view_time中添加其他参数，但这不起作用。有人可以帮我解决问题或者给我一个明智的想法来重新设计一个更好的数据库吗？这是我的代码。
models.py，Article包含view time
class Article(models.Model):
title = models.CharField(max_length=20)
content = MarkdownField()
date = models.DateField()
description = models.TextField(blank=True)
article_type = (
('Learning', (
('Python', 'python'),
('Java', 'java'),
)
),
('Life', 'life'),
('Other', 'other')
)
type = models.CharField(max_length=20, choices=article_type, blank=True)
lock = models.BooleanField(default=False)
view_time = models.IntegerField(default=1) # line 22 [error occured here]
def __str__(self):
return self.title
class Comment(models.Model):
name = models.CharField(null=True, blank=True, max_length=20)
comment = models.TextField()
auto_date = models.DateField(auto_now_add=True)
belong_to = models.ForeignKey(to=Article, related_name="under_comment", null=True, blank=True)
def __str__(self):
return self.name
view.py的一部分，当访问其中一篇文章时，view_time将被添加为1.
def blog_content(request, page_num, error_form=None):
context = {}
form = CommentForm
view_update = Article.objects.get(id=page_num)
view_update.view_time += 1
view_update.save()
context['detail'] = view_update
comments = Comment.objects.filter(belong_to=view_update)
context['comments'] = comments
print(comments.values().count())
if error_form is not None:
context['form'] = error_form
else:
context['form'] = form
return render(request, 'blog_content.html', context)
遵循错误
Applying blogapp.0018_comment_date...Traceback (most recent call last):##new added
File "manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/__init__.py", line 367, in execute_from_command_line
utility.execute()
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/__init__.py", line 359, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/base.py", line 305, in run_from_argv
self.execute(*args, **cmd_options)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/base.py", line 356, in execute
output = self.handle(*args, **options)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/commands/migrate.py", line 202, in handle
targets, plan, fake=fake, fake_initial=fake_initial
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/executor.py", line 97, in migrate
state = self._migrate_all_forwards(plan, full_plan, fake=fake, fake_initial=fake_initial)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/executor.py", line 132, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/executor.py", line 237, in apply_migration
state = migration.apply(state, schema_editor)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/migration.py", line 129, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/operations/fields.py", line 84, in database_forwards
field,
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/backends/sqlite3/schema.py", line 231, in add_field
self._remake_table(model, create_fields=[field])
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/backends/sqlite3/schema.py", line 113, in _remake_table
self.effective_default(field)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/backends/base/schema.py", line 221, in effective_default
default = field.get_db_prep_save(default, self.connection)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 755, in get_db_prep_save
prepared=False)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 1280, in get_db_prep_value
value = self.get_prep_value(value)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 1275, in get_prep_value
return self.to_python(value)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 1237, in to_python
parsed = parse_date(value)
File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/utils/dateparse.py", line 60, in parse_date
match = date_re.match(value)
TypeError: expected string or buffer
这是blogapp.0018_comment_date文件：
# -*- coding: utf-8 -*-
# Generated by Django 1.10 on 2017-07-26 12:19
from __future__ import unicode_literals
from django.db import migrations, models
class Migration(migrations.Migration):
dependencies = [
('blogapp', '0017_comment'),
]
operations = [
migrations.AddField(
model_name='comment',
name='date',
field=models.DateField(default=True),
),
]
答案 0 :(得分：1)
choices应该是一个可迭代的元组。你有三个层次的结构。
试试这个：
class Article(models.Model):
title = models.CharField(max_length=20)
content = MarkdownField()
date = models.DateField()
description = models.TextField(blank=True)
article_type = (
('Learning-Python', 'python'),
('Learning-Java', 'java'),
('Life', 'life'),
('Other', 'other')
)
type = models.CharField(max_length=20, choices=article_type, blank=True)
lock = models.BooleanField(default=False)
view_time = models.IntegerField(default=1)
如果您要向article_type添加类别，则需要将其添加为属性。
希望这有帮助。