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Adding multiple rows

Posted: Wed Jul 19, 2006 8:15 am
by someberry
Hi, does anyone know if it is possible to add values of multiple rows together? For instance:

Code: Select all

+----------+
| values   |
+----------+
| id       |
| quantity |
+----------+
There are hundreds of rows in this table, but I only want to add up the first three rows, ID numbers 1, 2, and 3.

Does anyone know if this can be done?
Thank you,
someberry

Posted: Wed Jul 19, 2006 8:31 am
by GM

Code: Select all

SELECT SUM(`quantity`) FROM `values` WHERE `id` IN ('1', '2', '3');
is one way, alternatively:

Code: Select all

SELECT SUM(`quantity`) FROM `values` ORDER BY `id` LIMIT 3;
should be another.

Hope this helps.

Posted: Wed Jul 19, 2006 8:41 am
by someberry
I probably should have mentioned that I am doing this in an UPDATE query, and am selecting multiple columns in the same row. Let me show you the current SQL I have:

Code: Select all

mysql_query("UPDATE `stock`, `total`
				SET total.1 = 
						stock.1 * 100 +
						stock.2 * 100 +
						stock.3 * 100 +
						stock.4 * 100
				WHERE   stock.stock_id IN ('0', '1', '2', '3')
				") or die(mysql_error());
I get no errors from the SQL, but it only ever uses the first row to update.

Thanks,
someberry.

Posted: Sun Jul 23, 2006 4:12 pm
by someberry
Anyone have any ideas?

Thanks,
Someberry