create table mytab 
( name varchar2(30), 
  value varchar2(60) )

insert into mytab values( 'home_phone', null )

insert into mytab values( 'cell_phone', '867-5309' )

commit

select coalesce( home.value, cell.value, 'None' ) 
from 
( select value from mytab where name = 'home_phone' ) home, 
( select value from mytab where name = 'cell_phone' ) cell

select coalesce( home.value, cell.value, 'None' ) 
from 
( select value from mytab where name = 'bad_phone' ) home, 
( select value from mytab where name = 'cell_phone' ) cell