Django - How to rename a model field using South?

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I would like to change a name of specific fields in a model:

class Foo(models.Model):
    name = models.CharField()
    rel  = models.ForeignKey(Bar)

should change to:

class Foo(models.Model):
    full_name     = models.CharField()
    odd_relation  = models.ForeignKey(Bar)

What's the easiest way to do this using South?

6 Answers

Here's what I do:

  1. Make the column name change in your model (in this example it would be myapp/models.py)
  2. Run ./manage.py schemamigration myapp renaming_column_x --auto

Note renaming_column_x can be anything you like, it's just a way of giving a descriptive name to the migration file.

This will generate you a file called myapp/migrations/000x_renaming_column_x.py which will delete your old column and add a new column.

Modify the code in this file to change the migration behaviour to a simple rename:

class Migration(SchemaMigration):

    def forwards(self, orm):
        # Renaming column 'mymodel.old_column_name' to 'mymodel.new_column_name'
        db.rename_column(u'myapp_mymodel', 'old_column_name', 'new_column_name')

    def backwards(self, orm):
        # Renaming column 'mymodel.new_column_name' to 'mymodel.old_column_name'
        db.rename_column(u'myapp_mymodel', 'new_column_name', 'old_column_name')
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