Re: aggregate function ?

> Any recomended good book for SQL ?

http://www.elsevier.com/wps/find/bookdescription.cws_home/706077/description#description
http://www.elsevier.com/wps/find/bookdescription.cws_home/710075/description#description

you can buy these books almost any where. However, I can only find the 2nd addition for the SQL
puzzles book on this website. I recommend the 2nd addition of the first.

> Yes, that for getting the accumulate of line 2 (50) first I have to
> know the accumulate of line 1 (75)
>
> Maybe with this example is more clear ...
> I changed the fields from mines, but as this table has more than
> 700.000 rows, I would like to put a LIMIT or WHERE clausule, but it
> doesn't work ....

Well the number of rows will probably be a problem, since the running total ( B ) is going to have
to scan most of the table for each row returned from your table ( A ). However, you can easily
limit the rows returned by table ( A ):

SELECT A.oid, A.detail, A.value_d, A.value_h
sum( B.value_d - B.value_h) AS value_sum
FROM Assentaments AS A
INNER JOIN Assentaments AS B
ON A.oid <= B.oid
WHERE A.oid BETWEEN 1 AND 100 -- you will have to pick the appropriate values
GROUP BY A.oid, A.detail, A.value_d, A.value_h
ORDER BY A.oid;

If ... sum( B.value_d - B.value_h) AS value_sum ... is not what you
really want, we can force your original syntax, but we will have to
reform you query a little. Also, getting it to work will probably
hurt performance a bit more.

> With this code it says: Error, Shcema 'a' doesn't exist ...

I am not sure about this error. It doesn't make sense to me. Could you Copy/Paste the actual
query with the associated error message?

Regards,
Richard Broersma Jr.