sum columns dynamically sql - sql

Question

I have multiple columns with some amount in a table and I want to show the total of all those amounts in the last Total column. I have a table in sql which looks somewhat like this,
A_Amt B_Amt C_Amt D_Amt E_Amt F_Amt ...
------------------------------------------------
15 20 25 30 35 40
i have written a query as
declare #xmlResult xml=
(
select *
from Foo
for xml PATH
);
SELECT Nodes.node.value('sum(*[contains(local-name(.), "_Amt")])', 'decimal(15,2)') AS Total
FROM
#xmlResult.nodes('//row') as Nodes(node);
but the result I am getting has only one column total but i want all the columns in resultant table like A_amt etc..

Answer 1

This should be what you need, BUT ATTENTION! You should NOT do this. Aggregate rows should NEVER be fetched together with the "raw" data. This is - in most cases - something your UI should do (or a report...)
declare #table TABLE(ID INT IDENTITY, a INT,b INT,c INT);
insert into #table VALUES(1,1,1),(2,3,4),(5,6,7);
SELECT a,b,c
FROM
(
SELECT ROW_NUMBER() OVER(ORDER BY t.ID) AS inx
,a,b,c
FROM #table AS t
UNION SELECT 999999,SUM(a),SUM(b),SUM(c)
FROM #table
) AS tbl
ORDER BY tbl.inx

Answer 2

I think this is what you are looking for, try this (replace spt_values with your table) :
USE MASTER
GO
declare #lsql nvarchar(max)
declare #lsql2 nvarchar(max)
declare #yourTable nvarchar(255) = 'spt_values'
Select #lsql = isnull(#lsql+'+','') + 'Case When ISNUMERIC('+name+') = 1 Then '+name+' else 0 end' from sys.Columns where Object_id = Object_id(#yourTable)
Print #lsql
SET #lsql2 = 'Select *, '+#lsql+' as Total_allcolumns From '+#yourTable+''
Exec(#lsql2)

Answer 3

Using Microsoft's system table is one way to achieve dynamic SQL and thus your goal. The code below is what you want or will at least get you started.
I wasn't sure what output you expected, so I included two outputs. Just use the one you want and discard the other one. Given your question, it is probably result1. (Result1 or Result2)
!!You have to write the table name in the script at the place indicated prior to executing it!!
--DISCLAIMER
--It assume you use SQL SERVER 2012. (Probably work on 2005+ with little adjustment)
--It assume data is in a table, (Not a view for example)
--Changing SQL SERVER version may break the code as Microsoft could change "system views".
--I don't remember well, but EXEC may be limited to 4000 characters in dynamic query. (But there is a work around, just look around if you need it)
--So use at your own risk
DECLARE #objectIDTable INT,
#AllColumnAdditionStatement NVARCHAR(MAX) = '',
#TableName NVARCHAR(250) = 'WriteYourTableNameHere',--!!!OVERWRITE THE TABLE NAME HERE
#Query NVARCHAR(MAX),
#AllSumStatement NVARCHAR(MAX) = ''
SELECT TOP 1 #objectIDTable = [object_id],
#AllColumnAdditionStatement = ''
FROM sys.objects
WHERE type_desc = 'USER_TABLE'
AND name = #TableName
SELECT #AllColumnAdditionStatement = #AllColumnAdditionStatement + 'CONVERT(DECIMAL(18, 4), (CASE WHEN ISNUMERIC(' + name + ') = 1 THEN ISNULL(' + name + ', ''0'') ELSE 0 END))' + ' + ',
#AllSumStatement = #AllSumStatement + name + 'Total = SUM(CONVERT(DECIMAL(18, 4), (CASE WHEN ISNUMERIC(' + name + ') = 1 THEN ISNULL(' + name + ', ''0'') ELSE 0 END))), ' + CHAR(10)
FROM sys.columns
WHERE object_id = #objectIDTable
AND name LIKE '%_Amt' --!!!Here is a column filter/selector to sum only column ending with _Amt
SELECT #AllColumnAdditionStatement = #AllColumnAdditionStatement + '0', --just too lazy to chop off last three char
#AllSumStatement = #AllSumStatement + 'Total_ = SUM(' + #AllColumnAdditionStatement + ')' + CHAR(10),
#Query = 'SELECT *,
Total_ = ' + #AllColumnAdditionStatement +'
FROM ' + #TableName
PRINT (#Query)
/********************************************************************************************/
EXEC (#Query) --or use sp_execute if you prefer
--Result1 : addition of all selected columns into total column with all column return as well
/********************************************************************************************/
SELECT #Query = 'SELECT ' + #AllSumStatement + '
FROM ' + #TableName
EXEC (#Query) --or use sp_execute if you prefer
--Result2 : Summation of all column individualy and summation of all of them into total column
/********************************************************************************************/