Re: activerecord and counting

James Byrne
2008-01-11T20:45:37Z

Binh Ly wrote:
> hello all,
>
> so i have the following situation
>
> company has_many products
> products has many parts
>
> i can do company.products .count and get back the product count
>
> what i''d like to know is if there is a more elegant way to get the
> number of parts for a given company outside of iterating through each
> product, counting its parts and then summing that number.
>
> the solution i have now works.  i was just wondering if there was a more
> elegant way of going about it.
>
> thanks,
>
> binh

Within rails? probably not.

You could, however, create a view in the target database and then use
that to return the desired values.  I

Or, if this type of reporting is a frequent requirement, and the the
parts per product is usually stable, then it might be worth while to
have a regularly scheduled or dynamically calculated roll-up of the part
count into a field in the product table and then report on that.