I'm often experimenting around creating different models, changing relations and so forth. This usually happens when starting a new project. At this phase I do not want to create any migrations but instead just get the thing up and running. So i very often do this:
rm db.sqlite3
rm -r project/apps/app/migrations/*
python manage.py makemigrations app
python manage.py migrate app
python manage.py createsuperuser
bla
bla
Is there any way to have this "reset" function more quickly? I frustratingly found out, that django does not allow superusers to be created by a shell script.
Is there any way to purge the db without removing the users?
How do you do this?
Try this:
Reset the Whole Database in Django
python manage.py flush
Reset an App Database Tables in Django
python manage.py migrate MyApp zero
Related
i am new to django developement after making changes to my model i tried to run the command python manage.py makemigrations my_app
it detects changes in my model and shows me the message
todoapp/migrations/0001_initial.py
- Create model confess
- Create model UserChoice
- Create model comment
but on executing python manage.py migrate my_appcommand i've got this message
No migrations to apply.
i usually do this after making changes in models, i don't know what happened now.
plss help me.
Firstly, try
python manage.py makemigrations my_app
python manage.py migrate
If this does not work and the project is still in development:
Delete migrations folder and pycache folder.
Delete db.sqlite3 (your database).
Make and apply migrations again.
I think this will work.
Delete all migrations files and __pychache__except__init__.py from your project and app. Also db.sqlite3 database then rerun makemigrations and migrate commands. It should solve your issue.
Suppose, we have a db's backup and a django program. The program do not have any migrations. First we restore db, that has created table and data. Now we want to make migrations from available db. Is it possible or not?
Yes, Django has the inspectdb method, which is described here.
But if the Django app already has the models defined that correspond to the backed up database, then you can just run makemigrations (follow #Shafikur's instructions).
Just go to your corresponding database terminals and delete all the records from you django_migrations table with
delete from django_migrations;
Go to terminal and run remove all files in migrations folder with
rm -rf <app>/migrations/
Reset all the migrations of the Django's built-in apps like admin with the command
python manage.py migrate --fake
Create initial migrations for each and every app:
python manage.py makemigrations <app>
To create initial fake migrations just run
python manage.py migrate --fake-initial
If I change certain attributes of a model, say add a column or change the type (or) size constraint etc, then I do
python manage.py sql myapp
python manage.py syncdb
The change doesnt get effected in the app. The change is effected only if i delete the table from my sql and give the commands again.
Is this the only way or are there any other easy ways to do it?
Yes. Get django-south and use it to migrate changes.
It's one of the most used django projects in the world and does exactly what you need.
Instead of running
python manage.py sycndb
You run
python manage.py schemamigration appname --initial
or
python manage.py schemamigration appname --auto
Or any of the other command combos. Check them out.
I'm deploying a project on a new development environment.
As I'm using South I did:
$ python manage.py syncdb --all
$ python manage.py migrate --fake
I used syncdb --all to apply actual state of models.
Then migrate --fake to mark all models as migrated.
But after that, my model is not on the last version (missing fields)
What am I doing wrong ?
I assume all my modifications have migrations.
If I do
$ python manage.py syncdb
It seems to create the first state since when I used South (that is expected)
But then
$ python manage.py migrate
Some tables appears as already created
Actually this, should have been fine for my case
$ python manage.py syncdb --all
$ python manage.py migrate --fake
Having to redeploy my app recently, I faced the same issue.
I just realized that I had a double initial migration on the model that were causing the problem
0001_initial.py
0002_initial.py
0003_auto__add_field_mytable_myfield.py
I simply deleted & renamed
0001_initial.py
0002_auto__add_field_mytable_myfield.py
Then redone the whole database deployment (obviously not forgetting to update the already applied migrations on my other hosts)
--fake option does not avoid errors while trying to create new migrations. It records that migrations have applied without actually applying them.
Also, you need --ignore-ghost-migrations or --delete-ghost-migrations to achieve what you are looking for.
To convert an existing project to south, you first need to convert the app
Now, if you have already run --fake, to recover, you can do this:
Go to ./manage.py dbshell
DELETE FROM south_migrationhistory WHERE id > 0; //Note that this would delete everything in the table.
If you want to remove migrations of a specific app,
DELETE FROM south_migrationhistory WHERE app_name = 'blah'
So I have a model that I wanted to add ImageField to, so I typed in
picture = models.ImageField(upload_to='media/images')
I then ran syncdb and went into the shell:
python2 manage.py syncdb
python2 manage.py shell
I then imported the model and tried
"model".objects.get(pk=1)
I get the error:
DatabaseError: no such column: people_people.picture
When I run manage.py sql for the model
"picture" varchar(100) NOT NULL
is in the database.
What solutions do you guys have? I can't delete the data in the database.
As noted in the documentation syncdb doesn't add columns to existing tables, it only creates new tables.
I suggest running
python manage.py sqlall <your_app>
Looking at the sql it outputs for the table you're changing, and then running
python manage.py dbshell
in order to manually issue an ALTER TABLE command.
In future, you might like to use a migration tool like South.
There are two possibilities that to get this error 1) You added extra field to model after doing the syncdb. 2) you added new class to model.py file in django.
Solution for this is:
First install south by using command
for windows: **easy_install south** //for that you need to go to the script folder of python folder in c drive.
for linux: **sudo easy_install south**
Then follow the steps which are included here migration tutorials
step1- python manage.py schemamigration your_app_name --initial
step-2 python manage.py migrate your_app_name
Hope this will help you.
As of 1.7 migrations within Django replaces South.
Create a new set of migration instructions by running the following command in terminal:
$ python manage.py makemigrations
Check the output in the migration folder it creates to make sure they make sense then run the following terminal command to complete the migrations:
$ python manage.py migrate
That's it.
Running migrations this way allows others to implement the same migrations instead of having to manually implement db changes on every machine using the code. On the new machine all they have to run is:
$ python manage.py migrate