Find by sql

Hi

I have the following code, which makes use of an sql statment to get the
results required.

However this just doesnt seem right for rails, as ive managed to develop
the whole project without using any other pure sql.

Is there a cleaner way of doing this, but gaining the same results.

thanks
scott

#sql to find all invoices
pSql = "SELECT DISTINCT invoices.id, invoices.invoice_number, 

invoices.approve_date, invoices.sent_date, invoices.paid_date
FROM projects, payments, invoices
WHERE projects.id = payments.project_id
AND payments.invoice_id = invoices.id
AND projects.id = " + params[:id] + "
ORDER BY invoices.id"

@invoices = Invoice.find_by_sql(pSql);