Updated the rake task to take STI into consideration.

tasks/paperclip_tasks.rake

@@ -14,10 +14,26 @@ def obtain_attachments
   end
 end
 
+def quote_table(table)
+  ActiveRecord::Base.connection.quote_table_name(table)
+end
+
+def quote_column(column)
+  ActiveRecord::Base.connection.quote_column_name(column)
+end
+
+def type_condition(klass)
+  if klass.superclass == ActiveRecord::Base
+    ""
+  else
+    "WHERE #{quote_column(klass.inheritance_column)} = '#{klass.name}'"
+  end
+end
+
 def for_all_attachments
   klass = obtain_class
   names = obtain_attachments
-  ids   = klass.connection.select_values("SELECT #{klass.primary_key} FROM #{klass.table_name}")
+  ids   = klass.connection.select_values("SELECT #{quote_column(klass.primary_key)} FROM #{quote_table(klass.table_name)} #{type_condition(klass)}")
 
   ids.each do |id|
     instance = klass.find(id)