Help with Order By AND ROWNUM by a student

[dbstudent]

I've tried several scripts and NONE of them have worked. I need to apply the Order By first, then limit to the top 10 Rows. Here are two I've tried, with both i'm getting a "command not properly ended" message:


--Question 8c 4 columns from Invoices table with alias' and two calculated columns and filter and sort with ROWNUM

SELECT  invoice_number AS "Number", invoice_total AS "Total", payment_total + credit_total AS "Credits", invoice_total - (payment_total + credit_total) AS "Balance Due"
FROM  invoices
WHERE invoice_total - (payment_total + credit_total) > 500
ORDER BY 4 DESC
  (SELECT *
  WHERE ROWNUM = 10)

SELECT  invoice_number AS "Number", invoice_total AS "Total", payment_total + credit_total AS "Credits", invoice_total - (payment_total + credit_total) AS "Balance Due"
FROM  invoices
WHERE invoice_total - (payment_total + credit_total) > 500 
      ( SELECT * from invoices
      ORDER BY invoice_total - (payment_total + credit_total) DESC
      );
WHERE ROWNUM = 10;

[Rabbit]

Please use code tags when posting code.

The correct syntax is this:

SELECT *
FROM (
   SELECT *
   FROM someTable
   ORDER BY someField
)
WHERE rownum <= 10;

[dbstudent]

WOW! You are amazing.....that answer worked like a charm....don't know why my book doesn't lay it out in those terms....
Sorry about the incorrect format, I will get it right next time.
Thanks!