How do I create a new database for an existing App using Django South and set default values?
I'm working with an OS project that uses South to migrate the database. I'm building a new database from scratch and I want to make sure South is setup so I can easily update the database in the future.
It seems this process should be:
- create the db
- syncdb
- migrate
However, when I try to migrate the databases, one of the the earlier migrations(migration 0004 and they go to 0009) throws an exception:
ValueError: You cannot add a null=False column without a default value.
I don't understand how to add a default value to migration 0004 so this exception isn't thrown.
The migrations don't need to be run through because the database is empty.
However, south_migrationhistory must contain a list of all migrations and when they were applied.
I tried to hack it and just add migration 0009 to the database manually, but this threw another error because the intermediary migrations had not been run. I also tried to add a field to database to see if I could figure out the syntax of add_column would look like with a default value of 0 supplied. The format looks totally different than these older migrations.
Here are the 2 different versions of the add_column syntax:
#0004 syntax:
db.add_column('experiments_dailyreport', 'test_group_size', orm['experiments.dailyreport:test_group_size'])
#0009 syntax:
syntax db.add_column('experiments_dailyreport', 'test_group_size', self.gf('django.db.models.fields.IntegerField')(default=0), keep_default=False)
So, I'm guessing there was a change in the South code between when 0004 was created and today.
Is there a way to build the database with syncdb and then somehow update south_migrationhistory without running manage.py migrate ?
If you have an existing app with South migrations, how would you build a new database from scratch?
I can't migrate because there is no default set on a integer field. How do I set a default in an older migration? The field doesn't even exist anymore.
syntaxes attempted:
db.add_column('experiments_dailyreport', 'test_group_size', orm['experiments.dailyreport:test_group_size'], {'default': 0})
#throws ValueError: Yo开发者_开发问答u cannot add a null=False column without a default value.
db.add_column('experiments_dailyreport', 'test_group_size', self.gf('django.db.models.fields.IntegerField')(default=0), keep_default=False)
#throws AttributeError: Migration instance has no attribute 'gf'
I'm using South-0.7.2-py2.7.egg
Andrew Godwin provided an answer:
Yes, use:
./manage.py syncdb --all
then:
./manage.py migrate --fake
This will, however, also ignore any migrations that add in data to the database.
syncdb
is no longer supported, instead, see this answer:
- Delete all the folders named 'migrations'.
- Go to terminal and run:
./manage.py makemigrations
./manage.py migrate --run-syncdb
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