SQL Query including pivot - sql

Question

I have done a query which include the left outer join and the pivot.
However I keep getting a bugs saying incorrect column.
SELECT * FROM
(select Max(datetimestamp)as datetimestamp, currentSet, tGroup_id from tPhos_Line_Operator
group by currentSet, tGroup_id)T
LEFT OUTER JOIN
(SELECT PO.tGroup_id AS G_ID, PO.CurrentSet AS cr,gP.tTest_id AS Header,convert(float,Po.Results) as Results from tPhos_Line_Operator PO
inner join tPhos_Line_Parameter pp
on PO.tPhos_Line_Parameter_id = PP.id
INNER JOIN tGroup_Parameter GP
on pp.tGroup_Parameter_id = gp.id
where PP.tPhosline_id=134)P
on T.tGroup_id = P.G_ID
AND T.CurrentSet = p.cr
PIVOT ( MAX(p.Results) For Header IN ([4],[23],[24])) AS pvt
Anyone know how to get the DateTimeStamp and the pivot record?
Which mean i will only have 4 columns in this case.
Currently i need to select * from.
I'm sorry still a junior in query.
Thanks in advance.
sample data could go here:
sample of expected result:
dateTime | currentset | tGroup_id | G_ID | cr | 4 | 23 | 24 |
2015-03-11 07:00:24.313 1 69 69 1 8.36 10 14.4
2015-03-12 00:31:58.257 2 69 69 2 9.12 8 14.4

Answer 1

I am making a guess. It appears that you want to "pivot" some results so you get to see these side by side instead of across multiple rows.
While PIVOT has been added into many SQL implementations, it is not the only way to achieve pivoted data nor is it always the best or easiest way to do it. Here is an old fashioned "pivot" that uses a set of case expressions and 'GROUP BY':
SELECT
PO.tGroup_id AS G_ID
, PO.CurrentSet AS cr
, MAX( datetimestamp ) AS datetimestamp
, MAX( CASE WHEN gP.tTest_id = 4 THEN CONVERT(float, Po.Results) END ) AS Results4
, MAX( CASE WHEN gP.tTest_id = 23 THEN CONVERT(float, Po.Results) END ) AS Results23
, MAX( CASE WHEN gP.tTest_id = 24 THEN CONVERT(float, Po.Results) END ) AS Results24
FROM tPhos_Line_Operator PO
INNER JOIN tPhos_Line_Parameter pp ON PO.tPhos_Line_Parameter_id = PP.id
INNER JOIN tGroup_Parameter GP ON pp.tGroup_Parameter_id = gp.id
WHERE PP.tPhosline_id = 134
GROUP BY
PO.currentSet
, PO.tGroup_id
Because you haven't supplied sample data I don't know the details but hopefully you can bend this to suit your data.
This is an alternative approach using the PIVOT operator but this also relies on using MAX() OVER(). One complication for using the PIVOT operator here is that you require a maximum datetime value as well as pivoted rows which is complex using the inbuilt pivot operator. I believe that complexity can be overcome by the MaxDateTime column seen below:
SELECT
MaxDateTime , CR, G_ID, [4], [23], [24]
FROM (
SELECT
PO.tGroup_id AS G_ID
, PO.CurrentSet AS cr
, gP.tTest_id AS Header
, MAX( PO.datetimestamp ) OVER (PARTITION BY PO.tGroup_id, PO.CurrentSet, gP.tTest_id) AS MaxDateTime
, CONVERT( float, Po.Results ) AS Results
FROM tPhos_Line_Operator PO
INNER JOIN tPhos_Line_Parameter pp ON PO.tPhos_Line_Parameter_id = PP.id
INNER JOIN tGroup_Parameter GP ON pp.tGroup_Parameter_id = gp.id
WHERE PP.tPhosline_id = 134
) AS sourve_tbl
PIVOT (MAX( Results ) FOR Header IN ([4], [23], [24])
) AS pvt_tbl
;

Answer 2

Yes your existing query is wrong.
I hv tried to correct it.
;With CTE as
(
select Max(datetimestamp)as datetimestamp, currentSet, tGroup_id
from tPhos_Line_Operator
group by currentSet, tGroup_id
)
Select * from
( SELECT PO.tGroup_id AS G_ID, PO.CurrentSet AS cr,gP.tTest_id AS Header
,convert(float,Po.Results) as Results
,T.*
from tPhos_Line_Operator PO
inner join tPhos_Line_Parameter pp
on PO.tPhos_Line_Parameter_id = PP.id
INNER JOIN tGroup_Parameter GP
on pp.tGroup_Parameter_id = gp.id
left join CTE T on T.tGroup_id = P.PO.tGroup_id
AND T.CurrentSet = PO.CurrentSet
where PP.tPhosline_id=134)tbl
PIVOT ( MAX(p.Results) For Header IN ([4],[23],[24])) AS pvt