Running total by grouped records in table - sql

Question

I have a table like this (Oracle, 10)
Account Bookdate Amount
1 20080101 100
1 20080102 101
2 20080102 200
1 20080103 -200
...
What I need is new table grouped by Account order by Account asc and Bookdate asc with a running total field, like this:
Account Bookdate Amount Running_total
1 20080101 100 100
1 20080102 101 201
1 20080103 -200 1
2 20080102 200 200
...
Is there a simple way to do it?
Thanks in advance.

Answer 1

Do you really need the extra table?
You can get that data you need with a simple query, which you can obviously create as a view if you want it to appear like a table.
This will get you the data you are looking for:
select
account, bookdate, amount,
sum(amount) over (partition by account order by bookdate) running_total
from t
/
This will create a view to show you the data as if it were a table:
create or replace view t2
as
select
account, bookdate, amount,
sum(amount) over (partition by account order by bookdate) running_total
from t
/
If you really need the table, do you mean that you need it constantly updated? or just a one off? Obviously if it's a one off you can just "create table as select" using the above query.
Test data I used is:
create table t(account number, bookdate date, amount number);
insert into t(account, bookdate, amount) values (1, to_date('20080101', 'yyyymmdd'), 100);
insert into t(account, bookdate, amount) values (1, to_date('20080102', 'yyyymmdd'), 101);
insert into t(account, bookdate, amount) values (1, to_date('20080103', 'yyyymmdd'), -200);
insert into t(account, bookdate, amount) values (2, to_date('20080102', 'yyyymmdd'), 200);
commit;
edit:
forgot to add; you specified that you wanted the table to be ordered - this doesn't really make sense, and makes me think that you really mean that you wanted the query/view - ordering is a result of the query you execute, not something that's inherant in the table (ignoring Index Organised Tables and the like).

Answer 2

I'll start with this very important caveate: do NOT create a table to hold this data. When you do you will find that you need to maintain it which will become a never ending headache. Write a view to return the extra column if you want to do that. If you're working with a data warehouse then maybe you would do something like this, but even then err on the side of a view unless you simply can't get the performance that you need with indexes,decent hardware, etc.
Here's a query that will return the rows the way that you need them.
SELECT
Account,
Bookdate,
Amount,
(
SELECT SUM(Amount)
FROM My_Table T2
WHERE T2.Account = T1.Account
AND T2.Bookdate <= T1.Bookdate
) AS Running_Total
FROM
My_Table T1
Another possible solution is:
SELECT
T1.Account,
T1.Bookdate,
T1.Amount,
SUM(T2.Amount)
FROM
My_Table T1
LEFT OUTER JOIN My_Table T2 ON
T2.Account = T1.Account AND
T2.Bookdate <= T1.Bookdate
GROUP BY
T1.Account,
T1.Bookdate,
T1.Amount
Test them both for performance and see which works better for you. Also, I haven't thoroughly tested them beyond the example which you gave, so be sure to test some edge cases.

Answer 3

Use analytics, just like in your last question:
create table accounts
( account number(10)
, bookdate date
, amount number(10)
);
delete accounts;
insert into accounts values (1,to_date('20080101','yyyymmdd'),100);
insert into accounts values (1,to_date('20080102','yyyymmdd'),101);
insert into accounts values (2,to_date('20080102','yyyymmdd'),200);
insert into accounts values (1,to_date('20080103','yyyymmdd'),-200);
commit;
select account
, bookdate
, amount
, sum(amount) over (partition by account order by bookdate asc) running_total
from accounts
order by account,bookdate asc
/
output:
ACCOUNT BOOKDATE AMOUNT RUNNING_TOTAL
---------- -------- ---------- -------------
1 01-01-08 100 100
1 02-01-08 101 201
1 03-01-08 -200 1
2 02-01-08 200 200