Adding Numbers out of a DB

[Justin Sampson]

I'm trying to make a rating script for my site. I'm making it like what site point has so that you can select a number between 1 and 10. I was thinking that what ever number they add would be a row in the table then I could add them all up and divide them by the number of rows.

I know how to do the division part but how could I add all the rows together?

Thanks,
Justin Sampson

[freakysid]

Assuming you have a table named "Ratings" which contains a columns named "points" and "ID_of_thing_being_rated" you could find the average of all rows with the following SQL (assuming your PHP variable $id holds the value you are searching for).

SELECT ( SUM(points) / COUNT(points) ) AS average
FROM Ratings
WHERE ID_of_thing_being_rated = '$id'

[Justin Sampson]

Thanks, thats exactly what I wanted. You just made my day

[freakysid]

Hi, I don't know what I was thinking when I wrote my post above - think I was tired.

Of course sql know what an average is. so you can write the query:

SELECT AVG(points) as average
FROM Ratings
WHERE ID_of_thing_being_rated = '$id'

Silly me!