if not exists(select * from sys.systable where lcase(table_name) = lcase('GuestPhotos')) then
	create table GuestPhotos(
	  "N" integer not null default autoincrement,
	  "Photo" long binary not null,
	  primary key("N")
	  )
end if;

go

if not exists(SELECT column_name from sys.syscolumn sc join sys.systable st on sc.table_id = st.table_id 
where LCase(table_name) = LCase('Guests') and LCase(column_name) = LCase('PhotoID')) then
  alter table Guests
    add "PhotoID" integer;
end if;