Calculating Running Totals - tsql

Question

I am trying to re-calculate a few different columns of data for a particular EmployeeID.
I want the hrs_YTD column to keep a running total. What is a good way of updating this info?
HRS_YTD currently has 0.00 values. I wan't to achieve the results in the table below.
ID | CHEKDATE | CHEKNUMBR | HRS | HRS_YTD
EN344944 | 01/1/2014 | dd1001 | 40.00 | 40.00
EN344944 | 01/8/2014 | dd1002 | 30.00 | 70.00
EN344944 | 1/15/2014 | dd1003 | 32.50 | 102.50
etc.....
DECLARE #k_external_id varchar(32)
SET #k_external_id = 'EN344944'
SELECT * INTO #tmpA
FROM dbo.gp_check_hdr a
WHERE a.EMPLOYID = #k_external_id
SELECT a.ID, a.CHEKNMBR, a.CHEKDATE,
(SELECT CAST(SUM(a.[hours]) as decimal(18,2)) FROM #tmpA b
WHERE (b.CHEKDATE <= a.CHEKDATE and YEAR(b.CHEKDATE) = 2013)) AS hrs_ytd
FROM #tmpA a
WHERE YEAR(a.CHEKDATE) = 2013
I really don't know if I can alias a table like I did with #tmpA b, but it's worked for me in the past. That doesn't mean its a good way of doing things though. Can someone show me a way to achieve the results I need?

Answer 1

havent tested this, but you can give this a try
DECLARE #k_external_id varchar(32)
SET #k_external_id = 'EN344944'
SELECT g1.primarykey, g1.ID,g1.CHEKDATE, g1.CHEKNUMBR, g1.HRS ,(SELECT SUM(g2.HRS)
FROM dbo.gp_check_hdr g2
WHERE g2.ID = #k_external_id AND
(g2.primarykey <= g1.primarykey)) as HRS_YTD
FROM dbo.gp_check_hdr g1
WHERE g1.ID = #k_external_id
ORDER BY g1.primarykey;
http://www.codeproject.com/Articles/300785/Calculating-simple-running-totals-in-SQL-Server

Answer 2

The way I'd do this is a combination of a computed column and a user defined function.
The function allows to aggregate the data. In a computed column, you can only work with fields of the same row, hence calling a function (which is allowed) is necessary.
The computed column allows this to work continuously without any additional queries or temp tables, etc. Once it's set, you don't need to run nightly updates or triggers or anything of the sort to keep the data updated, including when records change or get deleted.
Here's my solution ... and SqlFiddle: http://www.sqlfiddle.com/#!3/cd8d6/1/0
Edit:
I've updated this to reflect your need to calculate the running totals per employee. SqlFiddle also updated.
The function:
Create Function udf_GetRunningTotals (
#CheckDate DateTime,
#EmployeeID int
)
Returns Decimal(18,2)
As
Begin
Declare #Result Decimal(18,2)
Select #Result = Cast(Sum(rt.Hrs) As Decimal(18,2))
From RunningTotals rt
Where rt.CheckDate <= #CheckDate
And Year(rt.CheckDate) = Year(#CheckDate)
And rt.EmployeeID = #EmployeeID
Return #Result
End
The Table Schema:
Create Table [dbo].[RunningTotals](
[ID] [int] Identity(1,1) NOT NULL,
[EmployeeID] [int] NOT NULL,
[CheckDate] [datetime] NOT NULL,
[CheckNumber] [int] NOT NULL,
[Hrs] [decimal](18, 2) NOT NULL,
[Hrs_Ytd] AS ([dbo].[udf_GetRunningTotals]([CheckDate],[EmployeeID])), -- must add after table creation and function creation due to inter-referencing of table and function
Constraint [PK_RunningTotals3] Primary Key Clustered (
[ID] ASC
) With (
PAD_INDEX = OFF,
STATISTICS_NORECOMPUTE = OFF,
IGNORE_DUP_KEY = OFF,
ALLOW_ROW_LOCKS = ON,
ALLOW_PAGE_LOCKS = ON
)
) On [PRIMARY]
Result will tally up the YTD hrs for each year.
Note --
You cannot create the function or the table as is since they reference each other.
First, create the table with all but the computed column;
Then, create the function.
Finally, alter the table and add the computed column.
Here's a full running test script:
-- Table schema
Create Table [dbo].[RunningTotals](
[ID] [int] Identity(1,1) NOT NULL,
[EmployeeID] [int] NOT NULL,
[CheckDate] [datetime] NOT NULL,
[CheckNumber] [int] NOT NULL,
[Hrs] [decimal](18, 2) NOT NULL,
Constraint [PK_RunningTotals3] Primary Key Clustered (
[ID] ASC
) With (
PAD_INDEX = OFF,
STATISTICS_NORECOMPUTE = OFF,
IGNORE_DUP_KEY = OFF,
ALLOW_ROW_LOCKS = ON,
ALLOW_PAGE_LOCKS = ON
)
) On [PRIMARY]
Go
-- UDF Function to compute totals
Create Function udf_GetRunningTotals (
#CheckDate DateTime,
#EmployeeID int
)
Returns Decimal(18,2)
As
Begin
Declare #Result Decimal(18,2)
Select #Result = Cast(Sum(rt.Hrs) As Decimal(18,2))
From RunningTotals rt
Where rt.CheckDate <= #CheckDate
And Year(rt.CheckDate) = Year(#CheckDate)
And rt.EmployeeID = #EmployeeID
Return #Result
End
Go
-- Add the computed column to the table
Alter Table RunningTotals Add [Hrs_Ytd] As (dbo.udf_GetRunningTotals(CheckDate, EmployeeID))
Go
-- Insert some test data
Insert into RunningTotals Values (334944, '1/1/2014', '1001', 40.00)
Insert into RunningTotals Values (334944, '1/5/2014', '1002', 30.00)
Insert into RunningTotals Values (334944, '1/15/2014', '1003', 32.50)
Insert into RunningTotals Values (334945, '1/5/2014', '1001', 10.00)
Insert into RunningTotals Values (334945, '1/6/2014', '1002', 20.00)
Insert into RunningTotals Values (334945, '1/8/2014', '1003', 12.50)
-- Test the computed column
Select * From RunningTotals

Answer 3

Your sub query should work just fine.
I used a table variable in place of a temp table.
I also limited the results inserted in the temp table to 2013 to simplify the final select statement and limit the results in the temp table to just what you need. The only other thing is joining the sub query to the main query using the ID but what you have should work as you are limiting the result in your temp table to a specific ID.
DECLARE
#k_external_id varchar(32)
,#k_reporting_year int
SET #k_external_id = 'EN344944'
SET #k_reporting_year = 2013
DECLARE #temp TABLE(
ID NVARCHAR(32)
,CheckDate DATE
,CheckNumber NVARCHAR(6)
,HRS DECIMAL(18,2)
)
INSERT INTO #temp (
ID
,CheckDate
,CheckNumber
,HRS
)
SELECT
ID
,CHEKDATE
,CHEKNMBR
,[hours]
FROM
dbo.gp_check_hdr
WHERE
EMPLOYID = #k_external_id
AND YEAR(a.CHEKDATE) = #k_reporting_year
SELECT
ID
,CheckDate
,CheckNumber
,HRS
,(SELECT SUM(HRS) FROM #temp b WHERE a.ID = b.ID AND b.CheckDate <= a.CheckDate) AS hrs_ytd
FROM
#temp a