FIX: remove nullable dates post upgrade to Rails 4

db/migrate/20140827044811_remove_nullable_dates.rb

@@ -0,0 +1,42 @@
+class RemoveNullableDates < ActiveRecord::Migration
+  def up
+
+    # must drop so we can muck with the column
+    execute "DROP VIEW badge_posts"
+
+    # Rails 3 used to have nullable created_at and updated_at dates
+    #  this is no longer the case in Rails 4, some old installs have
+    #  this relic
+    #  Fix it
+    sql = "select table_name, column_name from information_schema.columns
+           WHERE  column_name IN ('created_at','updated_at') AND
+                  table_schema = 'public' AND
+                  is_nullable = 'YES' AND
+                  is_updatable = 'YES' AND
+                  data_type = 'timestamp without time zone'"
+
+    execute(sql).each do |row|
+      table = row["table_name"]
+      column = row["column_name"]
+
+      execute "UPDATE \"#{table}\" SET #{column} = CURRENT_TIMESTAMP WHERE #{column} IS NULL"
+      change_column table.to_sym, column.to_sym, :datetime, null: false
+    end
+
+    execute "CREATE VIEW badge_posts AS
+    SELECT p.*
+    FROM posts p
+    JOIN topics t ON t.id = p.topic_id
+    JOIN categories c ON c.id = t.category_id
+    WHERE c.allow_badges AND
+          p.deleted_at IS NULL AND
+          t.deleted_at IS NULL AND
+          NOT c.read_restricted AND
+          t.visible"
+
+  end
+
+  def down
+    # no need to revert
+  end
+end