create table target_table
(

name varchar(20),
address varchar(30),
state varchar (2),
Phone varchar(12),
concatinated varhcar(20))

insert into target_Table
(select
name,
address,
state,
Phone,
(case when (rtrim(Extra1) is not null and rtrim(Extra1) <>'') then rtrim(Extra1) else '' end +
case when (rtrim(Extra2) is not null and rtrim(Extra2) <>'') then ',' + rtrim(Extra2) else '' end +
case when (rtrim(Extra3) is not null and rtrim(Extra3) <>'') then ','+ rtrim(Extra3) else '' end ) as Concatinated