T-SQL Pivot Row to Column - sql

Question

I am using SQL Server 2012 and have a table that has the following columns:
ID, Date, CustomFieldName, CustomFieldValue
The CustomFieldName column has 100 values (I know how stupid this sounds) but for the sake of simplicity lets say they are CustomField1, CustomField2, CustomField3
I would like to create a pivot where the out put looks like
ID, Date, CustomField1, CustomField2, CustomField3 where the Max date of CustomFieldVaue's is aggregated.
I have failed horribly in this, but have some progress (though my max isnt right and getting a lot of wrong data)
Any help would be appreciated!
SELECT [date],[id], [CustomField1], [CustomField2], [CustomField3]
from
(
SELECT [date], [id], [CustomFieldValue], [CustomFieldName],
row_number() over(partition by [CustomFieldName] order by [CustomFieldValue]) rn
from CustomTable
) as st
pivot
(
max([CustomFieldValue])
FOR [CustomFieldName] in ([CustomField1], CustomField2, [CustomField3])
) as pivottable
order by [id]

Answer 1

Hope I got it right, you want to pivot the rows (COlumnName1,2,...etc) as columns, so I've made a little script that's ready to run.
I recommend CTE's when it comes to pivoting, makes it easier, if you want to see the whole structure of the query just do a select #xSqlString
set nocount on;
create table
#testTable
(
ID int identity(1,1),
[Date] datetime default getdate(),
CustomFieldName nvarchar(50),
CustomFieldValue date
);
declare
#i int = 0,
#xSqlStringPivot nvarchar(max) = '',
#xSqlString nvarchar(max) = '';
while(#i<=100)
begin
set
#xSqlStringPivot += concat('CustomFieldName',cast(#i as nvarchar(50)),char(13), case when #i<100 then ', ' else '' end);
insert into #testTable
(
CustomFieldName,
CustomFieldValue
)
values
(
concat('CustomFieldName', cast(#i as nvarchar(50))),
dateAdd(day,-#i,getdate())
);
set
#i += 1;
end;
select * from
#testTable
set
#xSqlString =
(
'with ctePiv as
(
select
t.CustomFieldName,
t.CustomFieldValue
from
#testTable t
)
select
*
from
ctePiv
pivot
(
max(customFieldValue) for customFieldName in
(
'+ #xSqlStringPivot +'
)
)p'
);
exec sp_executeSQL #xSqlString
drop table #testTable;
Edit 1
I am referencing the custom table on the while block, basically I'm iterating 100 times to populate the table with 100 rows. This is just to simulate your case.
while(#i<=100)
begin
set
#xSqlStringPivot += concat('CustomFieldName',cast(#i as nvarchar(50)),char(13), case when #i<100 then ', ' else '' end);
insert into #testTable
(
CustomFieldName,
CustomFieldValue
)
values
(
concat('CustomFieldName', cast(#i as nvarchar(50))),
dateAdd(day,-#i,getdate())
);
set
#i += 1;
end;
#xSqlStringPivot is just a small trick to make a list of elements (CustomFieldName0, CustomFieldName1, etc) and to concatenate it to a dynamic SQL string, notice that I'm doing this in the while block, I just concatenate 'CustomField' with the current iteration number and with a carry feed (space).