Upgrade script to manage database changement and correct errors from old

models

Creation of urn field when missing

4 files changed, 64 insertions, 0 deletions

diff --git a/chimere/.gitignore b/chimere/.gitignore
index fce19e4..dc3d5e7 100644
--- a/chimere/.gitignore
+++ b/chimere/.gitignore
@@ -1 +1,2 @@
 settings.py
+*.pyc
diff --git a/chimere/scripts/__init__.py b/chimere/scripts/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/chimere/scripts/__init__.py
diff --git a/chimere/scripts/upgrade.py b/chimere/scripts/upgrade.py
new file mode 100755
index 0000000..939bb4c
--- /dev/null
+++ b/chimere/scripts/upgrade.py
@@ -0,0 +1,62 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+import sys
+sys.path.append('.')
+
+from django.core.management import setup_environ
+import settings
+
+setup_environ(settings)
+
+from django.db import connection, transaction
+
+cursor = connection.cursor()
+
+from main.models import Area
+
+
+# early versions before 0.1: urn field doesn't exist for area
+
+import htmlentitydefs, re
+
+def slugfy(text, separator):
+    ret = u""
+    text = text.strip()
+    for c in text.lower():
+        try:
+           ret += htmlentitydefs.codepoint2name[ord(c)][0]
+        except:
+            ret += c
+    ret = re.sub("\W", " ", ret)
+    ret = re.sub(" +", separator, ret)
+    return ret.strip()
+
+query = """SELECT a.attname AS field FROM pg_class c, pg_attribute a
+    WHERE c.relname = 'main_area' AND a.attnum > 0 AND a.attrelid = c.oid
+          AND a.attname='urn';"""
+cursor.execute(query)
+transaction.commit_unless_managed()
+
+row = cursor.fetchone()
+if not row:
+    query_update = "ALTER TABLE main_area ADD COLUMN urn VARCHAR(50) \
+UNIQUE"
+    cursor.execute(query_update)
+    transaction.commit_unless_managed()
+    areas = Area.objects.all()
+    print " * urn field created in table main_area"
+    for area in areas:
+        urn = slugfy(area.name, "-")
+        area.urn = urn
+        area.save()
+        print " * area %s urn is now: %s" % (area.name, area.urn)
+
+    query = "ALTER TABLE main_area ALTER COLUMN urn SET not null;"
+    cursor.execute(query)
+    transaction.commit_unless_managed()
+    print " * urn field has now the constraint NOT NULL"
+
+# early versions before 0.1: save area with wrong SRID
+
+query = "SELECT AsText(ST_Transform(upper_left_corner, 4326)) from main_area;"
diff --git a/chimere/settings.py.example b/chimere/settings.py.example
index a87394b..58d12f3 100644
--- a/chimere/settings.py.example
+++ b/chimere/settings.py.example
@@ -132,4 +132,5 @@ INSTALLED_APPS = (
     'django.contrib.sessions',
     'django.contrib.sites',
     'chimere.main',
+    'chimere.scripts',
 )