Ниже код удовлетворит ваше требование
Create table #test
(id int,
person_id int,
ColumnName varchar(50),
StringValue varchar(50),
numericValue varchar(50)
)
insert into #test values (1,1,'FirstName','John',null)
insert into #test values (2,1,'Amount',null,'100')
insert into #test values (3,1,'PostalCode',null,'112334')
insert into #test values (4,1,'LastName','Smith',null)
insert into #test values (5,1,'AccountNumber',null,'123456')
--select * from #test
Declare @Para varchar(max)='',
@Para1 varchar(max)='',
@main varchar(max)=''
select @Para += ','+QUOTENAME(ColumnName)
from (select distinct ColumnName from #test) as P
set @Para1= stuff(@para ,1,1,'')
print @Para1
set @main ='select * from (
select coalesce(StringValue,numericValue) as Val,ColumnName from #test) as Main
pivot
(
min(val) for ColumnName in ('+@Para1+')
) as pvt'
Exec(@main)