2011/7/18 Martín Marqués <martin.marques@xxxxxxxxx>: > I'm building a table (which is a report that has to be printed) with a > bunch of items (up to 300 in some cases) that have unitary price > (stored in a numeric(9,2) field), how many there are, and the total > price for each item. At the end of the table there is a total of all > the items. > > The app is running on PHP and PG is the backend. > > The question is, how do I get the total of everything? > > Running it on PHP gives one value, doing a sum() on the backend gives > another, and I'm starting to notice that even using python as a > calculator gives me errors (big ones). Right now I'm doing the maths > by hand to find out who has the biggest error, or if any is 100% > accurate. I wouldn't even bother testing client implementations that are using floating point numbers to do the math -- they are going to be wrong. If you snoop around you should find math libraries that handle do a better job handling exact numbers for most popular languages. A few languages, like the hated COBOL, have them built in. merlin -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
