begin;
alter table application rename column versionname to versionname_old;
alter table application rename column versioncode to versioncode_old;
alter table application add column versionname varchar(12) not null default '';
alter table application add column versioncode varchar(12) not null default '';
update application set versionname = versionname_old;
update application set versioncode = versioncode_old;
commit;

