我正在研究django项目，并且在我的（测试）prod设置中遇到了一些迁移问题，因此我将所有相关数据转储出来，现在我正在从头开始设置数据库。
以下是发生的事情：
错误：
C:\Users\Sverker\Dropbox\Picrates>python manage.py makemigrations db_trans
C:\Users\Sverker\Dropbox\Picrates\picrates_project
Migrations for 'db_trans':
0001_initial.py:
- Create model Language
- Create model Markup
- Create model String
- Create model TransMarkup
- Create model TransString
- Add field trans_string to string
- Alter unique_together for string (1 constraint(s))
- Add field trans_markup to markup
- Alter unique_together for markup (1 constraint(s))
C:\Users\Sverker\Dropbox\Picrates>python manage.py migrate
C:\Users\Sverker\Dropbox\Picrates\picrates_project
Operations to perform:
Synchronize unmigrated apps: allauth, linkedin_oauth2, crispy_forms
Apply all migrations: account, sessions, admin, db_trans, sites, auth, contenttypes, parties, ped, socialaccount
Synchronizing apps without migrations:
Creating tables...
Installing custom SQL...
Installing indexes...
Running migrations:
Applying db_trans.0001_initial...Traceback (most recent call last):
File "manage.py", line 15, in <module>
execute_from_command_line(sys.argv)
File "C:\Python27\lib\site-packages\django\core\management\__init__.py", line 385, in execute_from_command_line
utility.execute()
File "C:\Python27\lib\site-packages\django\core\management\__init__.py", line 377, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Python27\lib\site-packages\django\core\management\base.py", line 288, in run_from_argv
self.execute(*args, **options.__dict__)
File "C:\Python27\lib\site-packages\django\core\management\base.py", line 338, in execute
output = self.handle(*args, **options)
File "C:\Python27\lib\site-packages\django\core\management\commands\migrate.py", line 161, in handle
executor.migrate(targets, plan, fake=options.get("fake", False))
File "C:\Python27\lib\site-packages\django\db\migrations\executor.py", line 68, in migrate
self.apply_migration(migration, fake=fake)
File "C:\Python27\lib\site-packages\django\db\migrations\executor.py", line 102, in apply_migration
migration.apply(project_state, schema_editor)
File "C:\Python27\lib\site-packages\django\db\migrations\migration.py", line 108, in apply
operation.database_forwards(self.app_label, schema_editor, project_state, new_state)
File "C:\Python27\lib\site-packages\django\db\migrations\operations\models.py", line 36, in database_forwards
schema_editor.create_model(model)
File "C:\Python27\lib\site-packages\django\db\backends\schema.py", line 213, in create_model
definition, extra_params = self.column_sql(model, field)
File "C:\Python27\lib\site-packages\django\db\backends\schema.py", line 125, in column_sql
default_value = self.effective_default(field)
File "C:\Python27\lib\site-packages\django\db\backends\schema.py", line 175, in effective_default
default = field.get_default()
File "C:\Python27\lib\site-packages\django\db\models\fields\__init__.py", line 719, in get_default
return self.default()
File "C:\Users\Sverker\Dropbox\Picrates\db_trans\models.py", line 9, in get_default_priority
max = Language.objects.all().aggregate(models.Max("fallback_priority"))["fallback_priority__max"]
File "C:\Python27\lib\site-packages\django\db\models\query.py", line 325, in aggregate
return query.get_aggregation(using=self.db, force_subq=force_subq)
File "C:\Python27\lib\site-packages\django\db\models\sql\query.py", line 402, in get_aggregation
result = query.get_compiler(using).execute_sql(SINGLE)
File "C:\Python27\lib\site-packages\django\db\models\sql\compiler.py", line 786, in execute_sql
cursor.execute(sql, params)
File "C:\Python27\lib\site-packages\django\db\backends\utils.py", line 81, in execute
return super(CursorDebugWrapper, self).execute(sql, params)
File "C:\Python27\lib\site-packages\django\db\backends\utils.py", line 65, in execute
return self.cursor.execute(sql, params)
File "C:\Python27\lib\site-packages\django\db\utils.py", line 94, in __exit__
six.reraise(dj_exc_type, dj_exc_value, traceback)
File "C:\Python27\lib\site-packages\django\db\backends\utils.py", line 65, in execute
return self.cursor.execute(sql, params)
File "C:\Python27\lib\site-packages\django\db\backends\sqlite3\base.py", line 485, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.OperationalError: no such table: db_trans_language
以下是创建的迁移：
# -*- coding: utf-8 -*-
from __future__ import unicode_literals
from django.db import models, migrations
import markupfield.fields
import db_trans.models
class Migration(migrations.Migration):
dependencies = [
]
operations = [
migrations.CreateModel(
name='Language',
fields=[
('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
('code', models.CharField(max_length=3)),
('language', models.CharField(max_length=50)),
('is_public', models.BooleanField(default=False)),
('fallback_priority', models.PositiveIntegerField(default=db_trans.models.get_default_priority, help_text=b'Lowest value will be first fallback language.', unique=True)),
],
options={
},
bases=(models.Model,),
),
migrations.CreateModel(
name='Markup',
fields=[
('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
('markup', markupfield.fields.MarkupField()),
('markup_markup_type', models.CharField(default=b'markdown', max_length=30, editable=False, choices=[(b'', b'--'), (b'html', b'html'), (b'plain', b'plain'), (b'markdown', b'markdown')])),
('_markup_rendered', models.TextField(editable=False)),
('language', models.ForeignKey(to='db_trans.Language')),
],
options={
},
bases=(models.Model,),
),
migrations.CreateModel(
name='String',
fields=[
('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
('string', models.CharField(max_length=256)),
('language', models.ForeignKey(to='db_trans.Language')),
],
options={
},
bases=(models.Model,),
),
migrations.CreateModel(
name='TransMarkup',
fields=[
('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
('key', models.CharField(unique=True, max_length=50, db_index=True)),
('verbose_name', models.CharField(max_length=200, null=True, blank=True)),
],
options={
'verbose_name': 'Translated Markup',
},
bases=(models.Model,),
),
migrations.CreateModel(
name='TransString',
fields=[
('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
('key', models.CharField(unique=True, max_length=50, db_index=True)),
('verbose_name', models.CharField(max_length=200, null=True, blank=True)),
],
options={
'verbose_name': 'Translated String',
},
bases=(models.Model,),
),
migrations.AddField(
model_name='string',
name='trans_string',
field=models.ForeignKey(related_name='strings', to='db_trans.TransString'),
preserve_default=True,
),
migrations.AlterUniqueTogether(
name='string',
unique_together=set([('trans_string', 'language')]),
),
migrations.AddField(
model_name='markup',
name='trans_markup',
field=models.ForeignKey(related_name='markups', to='db_trans.TransMarkup'),
preserve_default=True,
),
migrations.AlterUniqueTogether(
name='markup',
unique_together=set([('trans_markup', 'language')]),
),
]
models.py：
from django.db import models
from django.template.loader import render_to_string
from django.utils.translation import get_language
from markupfield.fields import MarkupField
def get_default_priority():
max = Language.objects.all().aggregate(models.Max("fallback_priority"))["fallback_priority__max"]
if max:
return max + 10
return 50
class Language(models.Model):
code = models.CharField(
max_length=3,
null=False,
blank=False,
)
language = models.CharField(
max_length=50,
)
is_public = models.BooleanField(
default=False,
)
fallback_priority = models.PositiveIntegerField(
null=False,
unique=True,
default=get_default_priority,
help_text="Lowest value will be first fallback language."
)
def __unicode__(self):
unicode = self.code
if self.language:
unicode += u" - " + self.language
return unicode
class TransPhrase(models.Model):
key = models.CharField(
max_length=50,
unique=True,
null=False,
blank=False,
db_index=True,
)
verbose_name = models.CharField(
max_length=200,
null=True,
blank=True,
)
@classmethod
def get_translation(cls, key, description=None):
trans_phrase, created = cls.objects.get_or_create(key=key)
if not description:
trans_phrase.verbose_name = description
trans_phrase.save()
return trans_phrase
def render(self, wrap, csrf_token):
raise NotImplementedError
class Meta:
abstract = True
class TransMarkup(TransPhrase):
def get_trans(self, language_code, use_fallback=True):
try:
return self.markups.get(language__code=language_code)
except Markup.DoesNotExist:
if use_fallback:
fallback_markups = self.markups.all().order_by("language__fallback_priority")
if fallback_markups:
return fallback_markups[0]
language = Language.objects.get(code=language_code)
return Markup(trans_markup=self, language=language)
def __unicode__(self):
return u"[" + self.key + u"]"
def render(self, wrap, csrf_token):
from db_trans.forms import SetTransMarkupForm
markup = self.get_trans(get_language(), use_fallback=(not wrap))
if wrap:
context = {
"csrf_token": csrf_token,
"form": SetTransMarkupForm(instance=markup),
"trans_markup": markup
}
return render_to_string("db_trans/set_markup.html", context)
else:
return markup
class Meta:
verbose_name = "Translated Markup"
class Markup(models.Model):
markup = MarkupField(
markup_type="markdown"
)
trans_markup = models.ForeignKey(
TransMarkup,
null=False,
related_name="markups",
)
language = models.ForeignKey(
Language,
null=False,
)
def __unicode__(self):
if self.markup.rendered:
return self.markup.rendered
return u"[" + self.trans_markup.key + u"]"
class Meta:
unique_together = ("trans_markup", "language")
class TransString(TransPhrase):
def get_trans(self, language_code, use_fallback=True):
try:
return self.strings.get(language__code=language_code)
except String.DoesNotExist:
if use_fallback:
fallback_strings = self.strings.all().order_by("language__fallback_priority")
if fallback_strings:
return fallback_strings[0]
language = Language.objects.get(code=language_code)
return String(trans_string=self, language=language)
def render(self, wrap, csrf_token):
from db_trans.forms import SetTransStringForm
string = self.get_trans(get_language(), use_fallback=(not wrap))
if wrap:
context = {
"csrf_token": csrf_token,
"form": SetTransStringForm(instance=string),
"trans_string": string
}
return render_to_string("db_trans/set_string.html", context)
else:
return string
class Meta:
verbose_name = "Translated String"
class String(models.Model):
string = models.CharField(
max_length=256
)
trans_string = models.ForeignKey(
TransString,
null=False,
related_name="strings"
)
language = models.ForeignKey(
Language,
null=False,
)
def __unicode__(self):
if self.string:
return self.string
return u"[" + self.trans_string.key + u"]"
class Meta:
unique_together = ("trans_string", "language")
非常感谢帮助！
答案 0 :(得分：0)
我知道这是一个老问题，但我最近有a similar error。进攻线可能是：
File "C:\Users\Sverker\Dropbox\Picrates\db_trans\models.py", line 9, in get_default_priority
max = Language.objects.all().aggregate(models.Max("fallback_priority"))["fallback_priority__max"]
所以在这里，您使用Language.objects.all()查询数据库。在实际运行迁移之前执行此行，而models.py与数据库本身之间仍然存在不一致。
尝试注释掉该行（以及对max的其他引用），然后重新运行迁移。这对我有用。