averaging sql row results

[1internet]

Ok I have a table, called reviews.

I want to work out the average for where a company=84 for example

 

So we have all these numbers for reviews

 

company   review

84                  1

84                  2

84                  3

84                  4

84                  3

89                  4

89                  1

89                  4

 

I want to be able to add them all up, and divide them by the number of rows, to create the average for the reviews. But only for a particular company.

So in this example I would want to extract 1+2+3+4+3 = 13/5 = 2.6

 

I have been trying to use msyql AVG(), but not much luck.

How do I go about doing this?

 

[requinix]

Use AVG() but make sure to GROUP BY the company ID - otherwise MySQL will average out all the values.

Edited March 7, 2013 by requinix

[Psycho]

Use AVG() but make sure to GROUP BY the company ID - otherwise MySQL will average out all the values.

 

Right, but since he only wants the average of the rows where company = 84 he wouldn't need the GROUP BY, just a where clause

 

@1internet, this will give you the average for a particular office

 

SELECT AVG(review) WHERE company = 84

 

OR you could run a query to get the average of every office (using GROUP BY as Requinex suggested)

 

SELECT company, AVG(review) as average
GROUP BY company