Loop through column values in Temp Table with N columns - sql

Question

I have a scenario inside a stored procedure where a temporary table will be generated with an unknown number of columns (Column1.....ColumnN). One of the columns will be the total\sum of few of the other columns.
The clients requirement is to show the percentage value of each column in comparison to the total column
(C1*100)/Total as P1 ,(C2*100)/Total as P2.....
I have really been unable to find a solution to this problem other than doing it in the front end using LINQ. I am wondering if there is any way to achieve this in SQL as that would give me performance benefits.The last thing I want to do is to loop through the rows and columns in C# which will hammer the server.

Answer 1

I had done, I just change according to you and you can read the comment for better understand. I feel the schemaname is dbo, else change it.
-------------1. first step --------------
--create table for exercise
CREATE TABLE [dbo].[tblTest](
[ID] [int] NULL,
[isTrue] [bit] NULL
) ON [PRIMARY]
--insert date
insert into tblTest values(1,'true'),(2,'false'),(3,'false'),(4,'true'),(5,'false')
select * from tbltest
-------------2. second step --------------
--now start to get column name one by one
DECLARE #TableName nvarchar(256) = '[dbo].[tblTest]',
#SearchStr nvarchar(128)='id', #SearchStr2 nvarchar(110) --this is used to get only particular column result, to check remove uncomment in cursor
SET #SearchStr2 = QUOTENAME('%' + #SearchStr + '%','''')
DECLARE #Columnname varchar(100) ,#ColumnIndex int --, #PurchaseQty int -- declare temp variable which you u
CREATE TABLE #Results (ColumnName nvarchar(370), ColumnValue nvarchar(3630), ColIndex int)
DECLARE getItemID CURSOR
FOR
select column_name, ordinal_position from INFORMATION_SCHEMA.COLUMNS where TABLE_NAME = PARSENAME(#TableName, 1)
OPEN getItemID
FETCH NEXT FROM getItemID INTO #Columnname, #ColumnIndex
WHILE ##FETCH_STATUS = 0
BEGIN
--select #Columnname, #ColumnIndex ;
INSERT INTO #Results
EXEC
(
'SELECT ''' + #ColumnName + ''', LEFT(' + #ColumnName + ', 3630) , '+ #ColumnIndex +'
FROM ' + #TableName + ' (NOLOCK) '
--remove this to get only particular column entry
--+' WHERE ' + #ColumnName + ' LIKE ' + #SearchStr2
)
FETCH NEXT FROM getItemID INTO #Columnname, #ColumnIndex
END
CLOSE getItemID
DEALLOCATE getItemID
select * from #Results
drop table #Results

Answer 2

DECLARE #cols AS NVARCHAR(max),
#calCols AS NVARCHAR(max),
#query AS NVARCHAR(max)
SELECT *
INTO #temptable
FROM (SELECT journeyid,
notchl,
Cast(Sum(Datediff(second, starttime, endtime)) AS FLOAT) AS
Duration
FROM (SELECT notchlog.*,
CASE
WHEN ( Isnumeric(notch) = 1
AND notch < 0 ) THEN 'DYN'
WHEN notch = 'I' THEN 'IDLE'
WHEN notch = 'C' THEN 'COASTING'
ELSE 'N' + notch
END AS NotchL
FROM notchlog)Sub1
GROUP BY journeyid,
notchl)SUB1
SELECT #cols = Stuff(( SELECT ',' + Quotename(notchl)
FROM #temptable
GROUP BY notchl
--order by value
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
, 1, 1, '')
SELECT #calCols = Stuff((SELECT ',' + 'ROUND(' + Quotename(notchl)
+ '*100/RunningTime,2) as '
+ Quotename(notchl)
FROM #temptable
GROUP BY notchl
--order by value
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
, 1, 1, '')
SET #query =N'Select * INTO #ResultTable FROM( SELECT Journeyid, '
+ #cols + ' from ( select Journeyid, NotchL, Duration from #TempTable Group By JourneyId,NotchL,Duration ) x pivot ( max(x.duration) for NotchL in ('
+ #cols
+ ') ) p ) Sub2 select NL.JourneyId,RunningTime,'
+ #calCols
+ N' from #ResultTable R INNER Join (Select JourneyID,Sum(DateDiff(second,starttime,endtime)) as RunningTime FROM NotchLog Group By JourneyID)NL ON NL.JourneyID=R.JourneyId INNER Join Journeys J ON J.JourneysID=R.JourneyID Drop Table #ResultTable '
EXEC Sp_executesql
#query;
DROP TABLE #temptable