Calculate a Running Total in SQL Server

0 votes

Imagine the following table (called TestTable):

id     somedate    somevalue
--     --------    ---------
45     01/Jan/09   3
23     08/Jan/09   5
12     02/Feb/09   0
77     14/Feb/09   7
39     20/Feb/09   34
33     02/Mar/09   6

I would like a query that returns a running total in date order, like:

id     somedate    somevalue  runningtotal
--     --------    ---------  ------------
45     01/Jan/09   3          3
23     08/Jan/09   5          8
12     02/Feb/09   0          8
77     14/Feb/09   7          15  
39     20/Feb/09   34         49
33     02/Mar/09   6          55

I know there are various ways of doing this in SQL Server 2000 / 2005 / 2008.

I am particularly interested in this sort of method that uses the aggregating-set-statement trick:

INSERT INTO @AnotherTbl(id, somedate, somevalue, runningtotal) 
   SELECT id, somedate, somevalue, null
   FROM TestTable
   ORDER BY somedate

DECLARE @RunningTotal int
SET @RunningTotal = 0

UPDATE @AnotherTbl
SET @RunningTotal = runningtotal = @RunningTotal + somevalue
FROM @AnotherTbl

Although I have heard there are problems with this because you can't always be sure that the UPDATE statement will process the data in the right sequence, it is still incredibly efficient. We might be able to find some conclusive solutions to that problem.

But perhaps others have ideas for different approaches. Can someone please help me with this?

Sep 9, 2022 in Database by Kithuzzz
• 38,010 points
1,228 views

1 answer to this question.

0 votes

The problem is that the SQL Server implementation of the Over clause is somewhat limited.

Oracle (and ANSI-SQL) allow you to do things like:

 SELECT somedate, somevalue,
  SUM(somevalue) OVER(ORDER BY somedate 
     ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) 
          AS RunningTotal
  FROM Table

There isn't a clear remedy to this issue provided by SQL Server. Though I will need to conduct some benchmarking on significant results, my intuition tells me that this is one of the rare situations in which a cursor is the fastest.

The update method is useful, but I think it's a bit flimsy. It appears that the order of the primary key will be followed if you are changing an entire table. Therefore, you will probably be secure if you set your date as a primary key ascending. However, you are depending on a SQL Server implementation detail that is not documented (especially if the query is ultimately handled by two procs). 

I hope this helps you.

answered Sep 11, 2022 by narikkadan
• 63,700 points

Related Questions In Database

0 votes
0 answers

What's the difference between a temp table and table variable in SQL Server?

We can build temp tables in SQL ...READ MORE

Feb 25, 2022 in Database by Vaani
• 7,060 points
464 views
0 votes
0 answers

Calculate time difference in minutes in SQL Server

I require the minutes-based time difference between ...READ MORE

Aug 13, 2022 in Database by Kithuzzz
• 38,010 points
1,035 views
0 votes
0 answers

Get week day name from a given month, day and year individually in SQL Server

I'm attempting to get a day name ...READ MORE

Aug 13, 2022 in Database by Kithuzzz
• 38,010 points
996 views
0 votes
0 answers

What represents a double in sql server?

I have several properties in C# which ...READ MORE

Aug 13, 2022 in Database by Kithuzzz
• 38,010 points
593 views
0 votes
1 answer

How do I UPDATE from a SELECT in SQL Server?

MERGE INTO YourTable T USING ...READ MORE

answered Feb 3, 2022 in Database by Vaani
• 7,060 points
633 views
0 votes
0 answers

How do I UPDATE from a SELECT in SQL Server?

INSERT INTO Table (col1, col2, col3) SELECT col1, ...READ MORE

Feb 4, 2022 in Database by Vaani
• 7,060 points
342 views
0 votes
1 answer

What is a stored procedure?

A stored procedure is a set of ...READ MORE

answered Feb 4, 2022 in Database by Neha
• 9,060 points
844 views
0 votes
1 answer

LEFT JOIN vs. LEFT OUTER JOIN in SQL Server

At the top level there are mainly ...READ MORE

answered Feb 4, 2022 in Database by Neha
• 9,060 points
1,711 views
0 votes
1 answer

Login failed for user 'sa'. The user is not associated with a trusted SQL Server connection. (Microsoft SQL Server, Error: 18452) in sql 2008

Solution Go to Start > Programs > Microsoft SQL Server > Enterprise Manager. Right-click the SQL ...READ MORE

answered Sep 12, 2022 in Database by narikkadan
• 63,700 points
903 views
0 votes
1 answer

Add a column with a default value to an existing table in SQL Server

Syntax: ALTER TABLE {TABLENAME} ADD {COLUMNNAME} {TYPE} {NULL|NOT ...READ MORE

answered Sep 12, 2022 in Database by narikkadan
• 63,700 points
2,126 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP