【已解决】django.db.utils.OperationalError: no such table: django_content_type错误。

对于新建的一个项目，新建的app，在数据库迁移的时候，执行了下面两条命令：

python manage.py makemigrations teacher_app,第一步成功

python manage.py migrate teacher_app,第二步失败，报错django.db.utils.OperationalError: no such table: django_content_type

解决方法：

python manage.py makemigrations teacher_app
python manage.py migrate

原因：

• migrate，负责对INSTALLED_APPS中的应用程序迁移。
• makemigrations, 负责基于你的模型修改创建一个新的迁移
• sqlmigrate, 展示迁移的sql语句
• showmigrations，其中列出了项目的迁移及其状态。

Python manger.py makemigrations：会在当前目录下生成一个migrations文件夹，该文件夹的内容就是数据库要执行的内容，会生成sql语句，可以使用python manger.py sqlmigrate app 0001查看具体的sql语句。

python manager.py migrate：执行之前生成的migrations文件，将该动作作用到数据库文件，生成表。

python manage.py migrate app_name：只执行app_name这个应用下的migrations文件，生成对应的表，对其它的migrations文件不执行。但是在创建一个新的项目后，会为我们自动生成一些migrations文件，只有在这些默认的migrations文件执行了，生成默认提供的表以后（如：django_content_type，auth_permission等），才能执行我们自己写的migrations文件，生成我们自己想要的表。

 

问题解决具体过程。

我的环境：Centos6.8+anaconda+pycharm+python3.7+Django1.8

这是我的项目建立过程：

1.建立项目

(Django) [[email protected] Django]# django-admin startproject teacher

(Django) [[email protected] Django]# cd teacher

(Django) [[email protected] teacher]# python manage.py startapp teacher_app

2.编写类，在teacher_app的models.py文件中

from django.db import models

# Create your models here.

class Teacher(models.Model):

    name = models.CharField(max_length=20)

    age = models.IntegerField()

    address = models.CharField(max_length=20)

    email = models.CharField(max_length=20)

    def __str__(self):

        return self.name

3.添加app到setting

INSTALLED_APPS = (

    'django.contrib.admin',

    'django.contrib.auth',

    'django.contrib.contenttypes',

    'django.contrib.sessions',

    'django.contrib.messages',

    'django.contrib.staticfiles',

    'teacher_app',

)

4.进行数据库迁移：

(Django) [[email protected] teacher]# python manage.py makemigrations teacher_app

Migrations for 'teacher_app':

  0001_initial.py:

    - Create model Teacher

(Django) [[email protected] teacher]# python manage.py migrate teacher_app

第二步失败。报错信息：Django.db.utils.OperationalError: no such table: django_content_type、  

 "Error creating new content types. Please make sure contenttypes "

RuntimeError: Error creating new content types. Please make sure contenttypes is migrated before trying to migrate apps individually.

具体报错信息：

(Django) [[email protected] teacher]# python manage.py makemigrations teacher_app

Migrations for 'teacher_app':

  0001_initial.py:

    - Create model Teacher

(Django) [[email protected] teacher]# python manage.py migrate teacher_app

Operations to perform:

  Apply all migrations: teacher_app

Running migrations:

  Rendering model states... DONE

  Applying teacher_app.0001_initial... OK

Traceback (most recent call last):

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/utils.py", line 64, in execute

    return self.cursor.execute(sql, params)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/sqlite3/base.py", line 318, in execute

    return Database.Cursor.execute(self, query, params)

sqlite3.OperationalError: no such table: django_content_type



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



Traceback (most recent call last):

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/contrib/contenttypes/models.py", line 65, in get_for_model

    ct = self.get(app_label=opts.app_label, model=opts.model_name)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/manager.py", line 127, in manager_method

    return getattr(self.get_queryset(), name)(*args, **kwargs)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/query.py", line 328, in get

    num = len(clone)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/query.py", line 144, in __len__

    self._fetch_all()

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/query.py", line 965, in _fetch_all

    self._result_cache = list(self.iterator())

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/query.py", line 238, in iterator

    results = compiler.execute_sql()

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 829, in execute_sql

    cursor.execute(sql, params)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/utils.py", line 79, in execute

    return super(CursorDebugWrapper, self).execute(sql, params)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/utils.py", line 64, in execute

    return self.cursor.execute(sql, params)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/utils.py", line 97, in __exit__

    six.reraise(dj_exc_type, dj_exc_value, traceback)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/utils/six.py", line 658, in reraise

    raise value.with_traceback(tb)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/utils.py", line 64, in execute

    return self.cursor.execute(sql, params)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/sqlite3/base.py", line 318, in execute

    return Database.Cursor.execute(self, query, params)

django.db.utils.OperationalError: no such table: django_content_type



During handling of the above exception, another exception occurred:



Traceback (most recent call last):

  File "manage.py", line 10, in <module>

    execute_from_command_line(sys.argv)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/__init__.py", line 338, in execute_from_command_line

    utility.execute()

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/__init__.py", line 330, in execute

    self.fetch_command(subcommand).run_from_argv(self.argv)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/base.py", line 390, in run_from_argv

    self.execute(*args, **cmd_options)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/base.py", line 441, in execute

    output = self.handle(*args, **options)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 225, in handle

    emit_post_migrate_signal(created_models, self.verbosity, self.interactive, connection.alias)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/sql.py", line 280, in emit_post_migrate_signal

    using=db)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/dispatch/dispatcher.py", line 201, in send

    response = receiver(signal=self, sender=sender, **named)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/contrib/auth/management/__init__.py", line 82, in create_permissions

    ctype = ContentType.objects.db_manager(using).get_for_model(klass)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/contrib/contenttypes/models.py", line 78, in get_for_model

    "Error creating new content types. Please make sure contenttypes "

RuntimeError: Error creating new content types. Please make sure contenttypes is migrated before trying to migrate apps individually.

错误信息告诉我在进行数据库迁移的时候应确保contenttypes被迁移了。接着我就开始迁移contenttypes，但还是报错，错误是“django.db.utils.OperationalError: no such table: auth_permission”，具体如下：

(Django) [[email protected] teacher]# python manage.py migrate contenttypes

Operations to perform:

  Apply all migrations: contenttypes

Running migrations:

  Rendering model states... DONE

  Applying contenttypes.0001_initial... OK

  Applying contenttypes.0002_remove_content_type_name... OK

Traceback (most recent call last):

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/utils.py", line 64, in execute

    return self.cursor.execute(sql, params)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/sqlite3/base.py", line 318, in execute

    return Database.Cursor.execute(self, query, params)

sqlite3.OperationalError: no such table: auth_permission



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



Traceback (most recent call last):

  File "manage.py", line 10, in <module>

    execute_from_command_line(sys.argv)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/__init__.py", line 338, in execute_from_command_line

    utility.execute()

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/__init__.py", line 330, in execute

    self.fetch_command(subcommand).run_from_argv(self.argv)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/base.py", line 390, in run_from_argv

    self.execute(*args, **cmd_options)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/base.py", line 441, in execute

    output = self.handle(*args, **options)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 225, in handle

    emit_post_migrate_signal(created_models, self.verbosity, self.interactive, connection.alias)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/core/management/sql.py", line 280, in emit_post_migrate_signal

    using=db)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/dispatch/dispatcher.py", line 201, in send

    response = receiver(signal=self, sender=sender, **named)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/contrib/auth/management/__init__.py", line 93, in create_permissions

    "content_type", "codename"

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/query.py", line 162, in __iter__

    self._fetch_all()

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/query.py", line 965, in _fetch_all

    self._result_cache = list(self.iterator())

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/query.py", line 1220, in iterator

    for row in compiler.results_iter():

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 783, in results_iter

    results = self.execute_sql(MULTI)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/models/sql/compiler.py", line 829, in execute_sql

    cursor.execute(sql, params)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/utils.py", line 79, in execute

    return super(CursorDebugWrapper, self).execute(sql, params)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/utils.py", line 64, in execute

    return self.cursor.execute(sql, params)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/utils.py", line 97, in __exit__

    six.reraise(dj_exc_type, dj_exc_value, traceback)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/utils/six.py", line 658, in reraise

    raise value.with_traceback(tb)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/utils.py", line 64, in execute

    return self.cursor.execute(sql, params)

  File "/root/anaconda3/envs/Django/lib/python3.7/site-packages/django/db/backends/sqlite3/base.py", line 318, in execute

    return Database.Cursor.execute(self, query, params)

django.db.utils.OperationalError: no such table: auth_permission

         后来我查资料，知道了类似django_content_type 、auth_permission等这样的表是默认创建的，刚开始以为是我的Django版本问题，但是之前照着视频学习的时候，运行没问题的。看来还是我的之前操作不到位。

我继续调试，输入命令：python manage.py showmigrations，这个命令是显示出Django项目中的所有migrations文件及其状态，

[x]　代表已经执行完毕的migrations文件，　[]表示未执行或执行失败的文件。

原来我是没有执行这些为我们默认配置的migrations。接下来我继续执行命令：python manage.py migrate ，这次没有带上应用名。

可以了，执行成功了，再检验一下，执行python manage.py showmigrations，所有的migrations都被执行了。

我再进一步确定数据库好不好用，查询数据，显示没问题。