Question

I have a parent table with two foreign key references to a child table. I am trying to come up with optimal TSQL (SQL Server 2008) that will “pivot” the child column into a row. The table structure and needed result set structure are below. What is the best way to make this work?

Thanks.

set nocount on
declare @parent table ( parentid int , parentword varchar(3) , childid int , childotherid int )
insert into @parent values ( 0 , 'a' , 1 , 3 )
insert into @parent values ( 1 , 'b' , 2 , 4 )

declare @child table ( childid int , childword varchar(3) )
insert into @child values ( 1 , 'ppp' )
insert into @child values ( 2 , 'qqq' )
insert into @child values ( 3 , 'rrr' )
insert into @child values ( 4 , 'sss' )


needed result set
a       ppp     rrr
b       qqq     sss

Answer 1

It is not pivoting.Join two times the child table with the parent table.See I have used the left join.If none of childid columns in parent tables are not null.Then you could use the inner join as well.

select p.parentword,c1.childword,c2.childword from @parent p
left join @child c1
on p.childid = c1.childid
left join @child c2
on p.childotherid = c2.childid