It is better to add constraints in the db for all uuid fields. That way uuid field will never get missed out. I see that for some tables there is a NOT NULL constraint.
-Koushik > -----Original Message----- > From: Min Chen [mailto:min.c...@citrix.com] > Sent: Friday, May 24, 2013 4:09 AM > To: dev@cloudstack.apache.org > Subject: Convention on UUID column > > Hi there, > > During API refactoring efforts, Rohit and I run into several issues due to > empty UUID column for existing DB entries. Since UUID was introduced later > in 3.0.x, we have to always conditionally handle existing customers with > empty UUID columns for different entities, causing much headache for > various upgrade cases. To make sure that we have a consistent upgrade base > for all 4.1 customers later, in schema-410to420.sql, we have added sql scripts > to populate UUID column of all pre-4.1 schema tables with values from their > ID column if UUID column is NULL. To make this work properly, we require > that all UUID columns should be populated with values when you add new > data into both pre-4.1 schema or post-4.1 schema. I just noticed that this > assumption may not be well known to community, since I am seeing this sql > in schema-410to420.sql: > > > INSERT INTO `cloud`.`vm_template` (id, unique_name, name, public, > created, type, hvm, bits, account_id, url, checksum, enable_password, > display_text, format, guest_os_id, featured, cross_zones, hypervisor_type) > > VALUES (10, 'routing-10', 'SystemVM Template (LXC)', 0, now(), 'SYSTEM', > 0, 64, 1, 'http://download.cloud.com/templates/acton/acton-systemvm- > 02062012.qcow2.bz2', '2755de1f9ef2ce4d6f2bee2efbb4da92', 0, 'SystemVM > Template (LXC)', 'QCOW2', 15, 0, 1, 'LXC'); > > > Instead, this should be modified as: > > > INSERT INTO `cloud`.`vm_template` (id, uuid, unique_name, name, public, > created, type, hvm, bits, account_id, url, checksum, enable_password, > display_text, format, guest_os_id, featured, cross_zones, hypervisor_type) > > VALUES (10, UUID(), 'routing-10', 'SystemVM Template (LXC)', 0, now(), > 'SYSTEM', 0, 64, 1, 'http://download.cloud.com/templates/acton/acton- > systemvm-02062012.qcow2.bz2', '2755de1f9ef2ce4d6f2bee2efbb4da92', 0, > 'SystemVM Template (LXC)', 'QCOW2', 15, 0, 1, 'LXC'); > > I have made this fix in master, but want to raise this topic to get > community's > attention on this. > > Thanks > -min >
