So I've got an API built in Django with Django Rest Framework and I now want to add a role based access control to it. For this I found the django-rest-framework-roles extension. I've got it installed, but I'm not really familiar with the usual authentication system in Django. It says I need to define the groups in the settings as
ROLE_GROUPS = [group.name.lower() for group in Group.objects.all()]
So I need the Group model and of course also the User model. As far as I understand, these are standard models. However, I don't have any tables in my DB for them. So I need a migration for it, but I'm unsure how I can do that.
I guess it should be really easy, but even on the relevant pages in the documentation I don't see any mention on how to add these models to my Django installation.
Could anybody enlighten me on this?
In your settings.py you have something like this:
INSTALLED_APPS = [
...
"django.contrib.auth",
...
]
That app has the Group and User models(included django app), so the first thing that you will do after config the database is migrate with this command./manage.py migrate, after migrate you can use importing them like this: from django.contrib.auth.models import User, Group
The standard User model in django has the table name auth_user.
The standard Group model has the table name of auth_group.
The database tables themselves are created once you have ran your first migration script after starting your project.
This is done from the command line with:
$ python manage.py migrate
I have walking on a strange way, but it is result of circumstances.
I had to been generate single models.py from exist postgres DB by inspect_db.
Next I fix some field (was a few problem with keys), and create 2 apps inside this project. So now I have 3 models.py (them are split models.py, whitch was generate by inspect_db). managed = True was added. Classes have same links and datatypes like in the database
Next I wish to integrate this models to exist database. I make migration, I migrate and in the end DB have only system django tables (auth_, django_migrations etc.) None from my classes (although migrate files were create). So I tryied to delete migrations catalogs and repeat makemigrations and migrate, but terminal threw it:
Operations to perform:
Apply all migrations: admin, auth, contenttypes, sessions
Running migrations:
No migrations to apply.
(forest-venv) user#user-HP-Z800-Workstation ~/MyProjects/forest-venv/lesoved $ python manage.py runserver 8001
Performing system checks...
If I try make migrates again - no changes. I tryied to delete info about my apps in django_migrations table - no result.
So my questions:
- It is possible to integrate new models into exist database (if names, keyes and formats is ok)?
- Integration is possible by the way where data from exist database is saved after migrations?
- How to return possobillity of make migrations? now it isn't work.
The trick when using an existing database is to make sure you start from a well-defined state: First get Django to the exact same state as your db, and only after that start making changes to your models. So these are the steps:
Check that your database doesn't have a django-migrations table, delete it using SQL if needed. (Note: I'm assuming this db isn't generated by Django to start with and you're creating a fresh django application)
Create your models with inspectdb. If needed, rename the models to have proper CamelCase. If you rename models or fields that would change the table or column name in the db, make sure to set db_table (Meta options of your model) and db_column (as field attribute).
Run manage.py makemigrations. Check the migration files for your models, just to be sure the names match with your db.
For your own apps, run manage.py migrate <app> --fake. This will add the migrations to django-migrations table in your db as if they ran, without actually running them.
Then run manage.py migrate to create the django provided tables (auth, contenttype, session etc...)
Now you are at the state where you can start changing things. If you change the model and run makemigrations it should create a migration just for your changes.
So I have this django installation in which there are a bunch of migration scripts. They look like so:
00001_initial.py
00002_blah_blah.py
00003_bleh_bleh.py
Now I know these are "database building" scripts which will take stuff defined in models.py and run them against the db to "create" tables and stuff.
I want to create a new table(so I created its definition in models.py). For this, I have copied another model class and edited its name and fields and it is all fine. Lets call this new model class 'boom'.
My question is now how do I "create" this boom table using the migration script and the boom model?
I am worried that I might accidentally disrupt anything that is already in DB. How do I run the migration to create only boom table? How do I create a migration script specifically for it?
I know that it has something to do with manage.py and running migrate or runmigration (or is it sqlmigrate?...im confused). While creating the boom table, I dont want the database to go boom if you know what I mean :)
First, create a backup of your database. Copy it to your development machine. Try things out on that. That way it doesn't matter if it does go "boom" for some reason.
The first thing to do is
python manage.py showmigrations
This shows all the existing migrations, and it should show that they have been applied with an [X].
Then,
python manage.py makemigrations
Makes a new migration file for your new model (name 00004_...).
Then do
python manage.py migrate
to apply it. To undo it, go back to the state of migrations 00003, with
python manage.py migrate <yourappname> 00003
There are two steps to migrations in Django.
./manage.py makemigrations
will create the migration files that you see - these describe the changes that should be made to the database.
You also need to run
./manage.py migrate
this will apply the migrations and actually run the alter table commands in SQL to change the actual database structure.
Generally adding fields or tables won't affect anything else in the database. Be more careful when altering or deleting existing fields as that can affect your data.
The reason for two steps is so that you can make changes on a dev machine and once happy commit the migration files and release to your production environment. Then you run the migrate command on your production machine to bring the production database to the same state as your dev machine (no need for makemigrations on production assuming that your databases started the same).
My question is now how do I "create" this boom table using the
migration script and the boom model?
./manage.py makemigrations
I am worried that I might accidentally disrupt anything that is
already in DB.
The whole point of migrations, is that it doesn't
I know that it has something to do with manage.py and running migrate
or runmigration
For more information please refer to : https://docs.djangoproject.com/en/1.10/topics/migrations/
And rest assured that your database will not go boom! :-)
I solved it simply, changing the name of the new model to the original name, and then I checked if there is the table in the database, if not, I just create a new table with the old name with just a field like id.
And then clear migrations and create new migrations, migrate and verify table was fixed in DB and has all missing fields.
If it still doesn't work, then change the model name back to a new one.
but when django asks you if you are renaming the model you should say NO to get the old one removed properly and create a new one.
This type of error usually occurs when you delete some table in dB manually, and then the migration history changes in the tables are lost.
But it is not necessary to erase the entire database and start from scratch.
yekabathula-macbookair2:roster yekabathula$ python manage.py migrate
Operations to perform:
Synchronize unmigrated apps: staticfiles, messages
Apply all migrations: admin, contenttypes, api, auth, sessions
Synchronizing apps without migrations:
Creating tables...
Running deferred SQL...
Installing custom SQL...
Running migrations:
Rendering model states... DONE
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying admin.0001_initial... OK
Applying api.0001_initial... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying sessions.0001_initial... OK
yekabathula-macbookair2:roster yekabathula$ python manage.py syncdb
/Library/Python/2.7/site-packages/django/core/management/commands/syncdb.py:24: RemovedInDjango19Warning: The syncdb command will be removed in Django 1.9
warnings.warn("The syncdb command will be removed in Django 1.9", RemovedInDjango19Warning)
Operations to perform:
Synchronize unmigrated apps: staticfiles, messages
Apply all migrations: admin, contenttypes, api, auth, sessions
Synchronizing apps without migrations:
Creating tables...
Running deferred SQL...
Installing custom SQL...
Running migrations:
No migrations to apply.
After doing python manage.py migrate, tables are not created in database from my models.py it is able to create other tables from django_session etc. Is there anything else that I need to follow here ?
I was facing a similar problem in Django 1.10 and none of the above solutions worked for me.
What eventually worked was running this command:
python manage.py migrate --fake myappname zero
This reset all migrations (to the zeroth state)
This followed by :
python manage.py migrate myappname
created the tables for me.
If you do not want to roll back to the initial(zero) state but say to the migration number 0005(the last migration that worked), you can instead do this:
python manage.py migrate --fake myappname 0005
And then proceed with the actual migrate:
python manage.py migrate myappname
More details in the docs
In my case the __init__.py file was missing from the APP/migrations/ folder. If you don't have one, all it needs is an empty __init__.py file.
I ran into the same problem. After lots of digging, I found the solution.
I'm using django 1.11.
If you want to start-over,
1)delete all the files in your migrations folder except __init__.py
2)drop database
3)create database
4)python makemigrations
5)python migrate
if you have reset_db, instead of 2nd and 3rd steps you can use reset_db.
python manage.py reset_db
I am using MySQL and get into this issue after deleting 0001_initial.py migration file and all the custom tables evolved from DB to try to regenerate all they...
Solved this issue simply deleting these rows in django_migrations table...
After that, $ python manage.py migrate command regenerates all my custom tables again.
I had a similar problem and just figured it out.I have multiple databases. My local one (the one not being updated) is a MySQL database. The others are MS SQL Server and MySQL. I have routers to the other databases since I do not manage them and had (in Django 1.6) used the routers to indicate allow_sync() = False. With 1.7, I changed that to allow_migrate() = False. BUT I DID NOT ADD A ROUTER FOR MY LOCAL DATABASE. The default appears to be allow_migrate() = False if there is not one. As a result, the migrations just failed silently ( Reference: https://docs.djangoproject.com/en/1.7/topics/db/multi-db/). I added a router for my local DB, setting allow_migrate() to return True and now my migrations actually create my tables.
Change managed = True (if it is set to False) in models.py
class Meta:
managed = False
db_table = 'table_name'
To
class Meta:
managed = True
db_table = 'table_name'
I had a similar issue. I did everything stated above but nothing worked. Then I realized I had not added my model name in admin.py file in my app.
Along with everything stated above you have to also add your model name in admin.py file. You have to add it like this:
admin.site.register(model name)
This can be very frustrating, but here is method that worked for me.
First, if you've deleted the migration file go ahead and create it again
python manage.py makemigrations
Then compare the migration file with the SQL raw code and if it fit then apply migration
python manage.py sqlmigrate [app_name] 0001
python manage.py migrate
or you can simply pipe it from your command line or terminal
python manage.py sqlmigrate [app_name] 0001 | [psql] db_name username
BEGIN
CREATE TABLE
ALTER TABLE
COMMIT
NOTE: In my case I'm using postgresql. Though engine is similar to other database langauge, you might not get expected result.
Delete existing tables of the models in MySQL database.
Delete migration folder under app folder.
Delete all relative migration records in the table
"django_migrations" from MySQL.
Now you get clear model and database. Use
python manage.py makemigrations and python manage.py migrate
to create tables.
Hope to help you.
try this one,
run,
python manage.py makemigrations app_name
above command will make migrations, if successful then run second command or
check if you have typo in Installed_app and also check for AppConfig module
python manage.py migrate app_name
if above was successful, this will create the table in db
This solved the problem for me (I am using MySQL workbench by the way):
Run this sql: SET FOREIGN_KEY_CHECKS = 0;
Select all the tables in your django database (click on the first table, then press and hold shift, then click on the last table). Then right click and choose "Drop n tables" (where n is the number of tables you just selected)
then run python manage.py migrate
Finally restore foreign key check settings by running this sql: SET FOREIGN_KEY_CHECKS = 1;
Note: Before taking this drastic measure, I tried what Paulo Pessoa said in his comment, but still I got "No migrations to apply." messages. However, this solved the issue.
If you want to do it only for your application not from all the apps then Clear your application migrations records from 'django_migrations' table in your DB.
Python manage.py makemigrtions
python
Problem: : When you apply migrations in django for the first time, django creates table of that model in database and marks somewhere in its own file(class):
`initial = True`
When you then tries to alter the schema of that table it firstly checks
if initial = True
if an initial class attribute isn’t found, a migration will be considered “initial”
In case the initial = True we need to use
python manage.py migrate --fake-initial
For an initial migration Django checks that all of those tables already exist in the database and fake-applies the migration if so. Similarly, for an initial migration that adds one or more fields Django checks that all of the respective columns already exist in the database and fake-applies the migration if so.
Fake initial migration uses both CreateModel() and AddField() methods.
Solution:
>> python manage.py makemigrations <AppName>
>> python manage.py migrate --fake-initial
To avoid deleting critical databases, you may also consider silencing properties below the Class Meta: for example this model:
class Blog(models.Model):
category = models.CharField(max_length=100)
title = models.CharField(max_length=100)
date_added = models.DateTimeField()
merits = models.CharField(max_length=300, blank=True)
demerits = models.CharField(max_length=300, blank=True)
class Meta:
managed = True
db_table = 'weblog'
verbose_name_plural = "Blog"
#property
def content_min(self):
return truncatechars(self.content, 50)
You can then run makemigrations and migrate and your table will be created.
Check if you have added your created app to you installed apps under settings.py.
The list should seem like this:
INSTALLED_APPS = [
'django.contrib.admin','django.contrib.auth','django.contrib.contenttypes',
'django.contrib.sessions', 'django.contrib.messages','django.contrib.staticfiles',
'YourCreatedApp',
]
in my case just one app's tables of project doesn't recreate!
and this line of code recreate them and successfully run!
python manage.py migrate --run-syncdb
however i couldn't find main reason caused this kind of problem!
Delete database
delete migration folder
run migrate command
run makemigrations command
run migrate command
It will create all tables perfectly
Change from sqlite3 to mysql in settings.py
Make sure you have correct information regarding database name and username-password
Delete existing migration
Make migration
And then migrate
Make sure each app's migrations folder has a __init__.py file.
I had a similar issue, the connection with DB was set correctly as all the django admin tables were created on DB side. However, no models appeared in models.py
What worked for me is running in the console:
python manage.py inspectdb > models.py
which wrote everything into a new models.py file which then I replaced with the one I had in the app folder. Then I could alter the
managed = False
into
managed = True
here the link to the documentation: https://docs.djangoproject.com/en/3.1/howto/legacy-databases/
If you are a begginer like me make sure your classes extend models.Model. Then makemigrations and migrate.
class Cook(models.Model):
email = models.Field()
I solved a similar problem by doing this:
Delete all migration files and pycache so what retains is init.py
Comment all implementations of that table in models, serializers, admin, urls and views
Do python manage.py makemigrations
Do python manage.py migrate
Then, uncomment all implementations of that table in models, serializers, admin, urls and views
Then, do python manage.py makemigrations
Then, do python manage.py migrate
To elaborate on #Leman-Kirme 's answer.
I had a similar problem where the table for the model I added into models.py of one of my apps wouldn't get created when making and applying migrations. I tried different solutions but nothing seemed to work and I really didn't want to flush my databases. So what I did was:
Delete all the files in the migrations folder except for _init_.py
Delete all records in databases' django_migrations tables.
Manually make a migration file (copied from another project and changed the content so that migration would only make a model that I was having troubles with). Please, note, that it seems like it should be initial migration, i.e. 0001_initial.py
Run it.
Voila, here comes the table!
If you want / need, instead of deleting previous migrations' files and records in the databases, you could backup them and restore afterwards. You gonna need to edit name of your manually-created migration from 0001_initial to something like <number_of_existing_migrations>_fix
That worked for me (but I ignored step 6), I hope someone finds this useful as well!
Gist: => Delete entry from django_migrations and run the migrate command again.
This answer takes help from other answers, but still writing as there are different cases and my answer might help in your case.
After creating migration, I think by mistake I ran the command python manage.py migrate campaign --fake I am not sure if it did some wrong thing, so now running python manage.py migrate campaign was not creating tableSo what solved for me is--
in mysql shell run
select * from django_migrations; Note the id of last migration which is creating problem in my case it was 62delete from django_migrations where id = 62Now I ran the migration again, and it worked this time. with command python manage.py migrate campaign i.e. required table was created as a result of applying migration
The problem I discovered working with Postgres is that I had not set the schema. I the original question is one of those gotchas that may have a number of different answers, so if the other answers are not working for you just check this.
The "problem" is that Postgres has an additional "namespace" layer which means you can specify the database but there can still be a whole set of tables, still in the same database, but in another schema or namespace.
The tables in this schema may be unreachable because the user being used to connect does not have permissions, or in fact the schema has been specified, but the tables were created in a different schema, or even you haven't specified the schema this time and are looking in the public schema while the tables have been created in another schema.
So the solution is to set the schema correctly, to what you intend, in every location and place that you use it. This boils down to correct database settings in all the settings files you are using, and logging in to the right schema and user when you inspect the database manually.
For example:
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
'OPTIONS': {'options': f'-c search_path={"foobar"}'},
'NAME': 'foo',
'USER': 'bar',
'PASSWORD': 'barpass',
'HOST': 'baz.example.com',
'PORT': 5432,
},
}
The database name here is foo, the username is bar and the schema name is foobar. Adding this line to the OPTIONS parameter defaults the schema for all operations.
For other usage, within Postgres, you can display the current search_path, and alter it for the current session, or "permanently" for the database:
SHOW search_path;
SET search_path=foobar,public;
ALTER DATABASE foo SET search_path TO foobar;
If your problem was that Django was creating your tables, but just in the wrong schema or under different permissions, I hope this has resolved your issue.
This kind-of thing was happening to me when I would try to reset my DB. Nothing else would work to get django to recognize my tables except:
python manage.py migrate --run-syncdb
In my case those solutions didn't work to me
I have to:
Create a new app: py manage.py startapp new_app_name
Copy all the files in my new app
Run: py manage.py makemigrations
Run: py manage.py migrate
It works to me, I hope it could be useful for you too
Below commands worked for me
python manage.py makemigrations app_name
python manage.py migrate app_name
I had the same issue and lol I just forgot to change my engine to the needed one
I have created a UserProfile field in order to add a favorites functionality to my site. Using Django's recommendation, I created a UserProfile model as follows at the bottom
Unfortunately, I already had the rest of my database created, and so I need to either use a migration utility or manually edit my database. However, I do not have sufficient permissions to utilize a migration utility, so I have to edit the database directly, and am struggling to do so.
This answer is similar to what I want to accomplish, but I can't quite get the syntax to work in my case.
MySQL - One To One Relation?
class UserProfile(models.Model):
user = models.ForeignKey(User, unique=True)
favorites = models.ManyToManyField(Media, related_name='favorited_by')
In my experience, the best migration utility is South. Once you've installed and added it to your settings, you'll need to create initial migrations for your existing modules using
./manage.py schemamigration --initial my_module,
which will include the one containing your UserProfile model, then from there you can migrate using
manage.py migrate my_module.
The real power in using a utility like this is portability and reversibility. You can migrate forward and backward as needed, and you'll be able to bring your schema to virtually any SQL database without all the fuss of rebuilding using SQL directly.
I would certainly agree with Steves recommendation to use South.
However if you for some reason wouldn't want to, you can issue the following command:
python manage.py sql <appname>
This will output the SQL statements which django will use to create your tables. This can then be used to manually modify the database.