Changes between Version 4 and Version 5 of Tutorial1

Timestamp:

04/03/09 13:58:15 (4 years ago)

Author:

andrew

Comment:

--

Tutorial1

@@ -69 +69 @@
 Created 0001_initial.py.
 }}}
+
+As you can see, it has made our `southdemo/migrations` directory for us, as well as putting an __init__.py file in it (to mark it as a Python package - this is also required).
+
+If you open up the migration file it made - `southdemo/migrations/0001_initial.py` - you'll see this:
+
+{{{
+#!python
+from south.db import db
+from django.db import models
+from southdemo.models import *
+
+class Migration:
+    
+    def forwards(self, orm):
+        
+        # Adding model 'Lizard'
+        db.create_table('southdemo_lizard', (
+            ('age', models.IntegerField()),
+            ('id', models.AutoField(primary_key=True)),
+            ('name', models.CharField(max_length=30)),
+        ))
+        db.send_create_signal('southdemo', ['Lizard'])
+        
+        # Adding model 'Adopter'
+        db.create_table('southdemo_adopter', (
+            ('lizard', models.ForeignKey(orm.Lizard)),
+            ('id', models.AutoField(primary_key=True)),
+            ('name', models.CharField(max_length=50)),
+        ))
+        db.send_create_signal('southdemo', ['Adopter'])
+        
+    
+    
+    def backwards(self, orm):
+        
+        # Deleting model 'Lizard'
+        db.delete_table('southdemo_lizard')
+        
+        # Deleting model 'Adopter'
+        db.delete_table('southdemo_adopter')
+}}}
+
+Migrations in South are, as you can see, just Migration classes with forwards() and backwards() methods, which get run as you go forwards or backwards over the migration respectively.
+
+Each method gets an 'orm' parameter, which contains a 'fake ORM' - it will let you access any frozen models for this migration (details on frozen models are covered in [wiki:Tutorial3 part three of the tutorial).
+
+Most of the time, you can get `startmigration` to write either all or most of a migration for you; continue to [wiki:Tutorial2 part two of the tutorial] for more about changing models.