Fix postgres sequences

When manually assigning a value to AutoField, sequences must be updated
manually.

https://docs.djangoproject.com/en/1.11/ref/databases/#manually-specifying-values-of-auto-incrementing-primary-keys

cof/migrations/0014_move_profile.py

@@ -4,11 +4,15 @@ from __future__ import unicode_literals
 from django.db import migrations, models
 from django.db.models import F
 
+from utils.models import sqlsequencereset
+
 
 def profiles_to_gestion(apps, schema_editor):
     OldProfile = apps.get_model('cof', 'CofProfile')
     NewProfile = apps.get_model('gestion', 'Profile')
 
+    connection = schema_editor.connection
+
     # New profiles are massively imported from the old profiles.
     # IDs are kept identical to ease the migration of models which were
     # referencing the CofProfile model.
@@ -30,6 +34,8 @@ def profiles_to_gestion(apps, schema_editor):
 
     NewProfile.objects.bulk_create(new_profiles)
 
+    sqlsequencereset([NewProfile], conn=connection)
+
     OldProfile.objects.all().update(profile_id=F('id'))
 
 

cof/migrations/0016_move_event.py

@@ -3,6 +3,8 @@ from __future__ import unicode_literals
 
 from django.db import migrations
 
+from utils.models import sqlsequencereset
+
 
 def event_to_gestion(apps, schema_editor):
     # Fetching the models that have be moved from cof to gestion
@@ -11,6 +13,8 @@ def event_to_gestion(apps, schema_editor):
     Location = apps.get_model('gestion', 'Location')
     Association = apps.get_model('gestion', 'Association')
 
+    connection = schema_editor.connection
+
     # The old Event.location field becomes a table: we need to create an entry
     # in this table for each value of the old `location` field.
     locations = set()  # A set to prevent duplicate entries
@@ -31,6 +35,8 @@ def event_to_gestion(apps, schema_editor):
         for event in new_events
     ])
 
+    sqlsequencereset([NewEvent], conn=connection)
+
     # Do not forget to link all the existing event to the COF association
     cof_assoc = Association.objects.get(name="COF")
     cof_assoc.events.add(*NewEvent.objects.all())
@@ -57,6 +63,7 @@ def event_to_gestion(apps, schema_editor):
             ToModel(**values)
             for values in FromModel.objects.values()
         ])
+        sqlsequencereset([ToModel], conn=connection)
 
 
 class Migration(migrations.Migration):

utils/models.py

@@ -0,0 +1,17 @@
+from django.core.management.color import no_style
+from django.db import connection
+
+
+def sqlsequencereset(models, conn=connection):
+    """
+    Update sequences of fields of `models`.
+
+    This function should be called after manually assigning a value to an
+    `AutoField`.
+    https://docs.djangoproject.com/en/1.11/ref/databases/#manually-specifying-values-of-auto-incrementing-primary-keys
+    """
+    sequence_sql = conn.ops.sequence_reset_sql(no_style(), models)
+    if sequence_sql:
+        with conn.cursor() as cursor:
+            for line in sequence_sql:
+                cursor.execute(line)