alter table subnet add column registerip1 varchar(15);
update subnet set registerip1 = '' where registerip1 is NULL;
alter table subnet alter registerip1 set not null;
alter table subnet alter registerip1 set default '';

alter table subnet add column registerip2 varchar(15);
update subnet set registerip2 = '' where registerip2 is NULL;
alter table subnet alter registerip2 set not null;
alter table subnet alter registerip2 set default '';

alter table network add column registerip1 varchar(15);
update network set registerip1 = (select registerip1 from building where id = network.building) where registerip1 IS NULL;
alter table network alter registerip1 set not null;
alter table network alter registerip1 set default '';

alter table network add column registerip2 varchar(15);
update network set registerip2 = (select registerip2 from building where id = network.building) where registerip2 IS NULL;
alter table network alter registerip2 set not null;
alter table network alter registerip2 set default '';

alter table building drop column registerip1;
alter table building drop column registerip2;
