django 1.7 migrations — how do I clear all migrati

问题:

So I'm rapidly iterating on a django app at the moment and I'm constantly adjusting models.py. Over the course of a day or two of programming and testing I generate a couple dozen migration files. Sometimes I really tear the schema apart and completely re-do it. This causes the migration process to complain a great deal about defaults and null values and so on. If possible, I would just like to scratch all the migration stuff and re-start the migrations now that I finally know what I'm doing. My approach thus far has been the following:

1. delete everything in the migrations folder except for __init__.py.
2. drop into my PostgreSQL console and do: DELETE FROM south_migrationhistory WHERE app_name='my_app';
3. while at the PostgreSQL console, drop all of the tables associated with my_app.
4. re-run ./manage.py makemigrations my_app - this generates a 0001_initial.py file in my migrations folder.
5. run ./manage migrate my_app - I expect this command to re-build all my tables, but instead it says: "No migrations to apply."

What gives?

Also, is the south_migrationhistory database table still in play now that I've dumped South and have switched to Django 1.7?

Thanks.

回答1:

So the step-by-step plan I outlined in my question does work, but instead of deleting rows from the south_migrationhistory database table, I had to delete rows from the django_migrations database table.

The command is: DELETE FROM django_migrations WHERE app='my_app'

Once this is done, you will be able to re-run your migrations from scratch.

回答2:

I just wanted to put all the steps into a command format:

NOTE: The commands below are pretty destructive, it is a means to start from scratch as the OP asked.

After a comment from mikeb I thought to add this line:

PRE - CHECK WHAT FILES YOU WOULD DELETE

find . -path *migrations* -name "*.py" -not -path "*__init__*"

Then, adjust the command in step 1 to one that works for your dev environment.

1. remove all the migrations from all the apps:

find . -path *migrations* -name "*.py" -not -path "*__init__*" -exec rm {} \; # make sure to be in your projects path

2. recreate the whole database:

sudo -u postgres bash -c "psql -c \"DROP DATABASE rootedin;\""
sudo -u postgres bash -c "psql -c \"CREATE DATABASE rootedin;\""
sudo -u postgres bash -c "psql -c \"GRANT ALL PRIVILEGES ON DATABASE rootedin to vagrant;\"" # vagrant is my current user

3. get your db up to date:

python3 manage.py makemigrations
python3 manage.py migrate