I don't think you want or need a pivot for this. However to be able to answer your question you first need to help us understand the actual issue. We need to see ddl and sample data. I took a shot at creating those from what you posted.

create table #Something

(

ID int,

Product1 int,

Product2 int,

Product3 int

)

insert #Something

select 1, 1, null, null union all

select 2, 1, 2, null union all

select 3, 3, 1, null union all

select 4, 2, 3, 1

So based on that sample data what should the output be?