Select *
from customers c, invoices i, shipment_info si
where c.customer_id = i.customer_id
    and i.amount > 999.99
    and i.invoice_id = si.invoice_id(+)  -- added to show how outer joins can be supported in this style
order by i.amount, c.name

SELECT *
  FROM customers c, invoices i, addresses a
 WHERE c.customer_id = i.customer_id
   AND i.amount > 999.99
 ORDER BY i.amount, c.name

SELECT *
FROM numbers
JOIN letters
ON 1=1

Select c.name, Sum(d.Amount)
 From customer c
    Left Join Invoice I
        On i.custId = c.custId
            And i.SalesDate Between '8/1/2009'
                      and '8/31/2009 23:59:59'
            And i.ProcessDate Is Not Null
    Left Join InvoiceDetails d
        On d.InvoiceId = i.InvoiceId
            And d.Product = 'widget'
 Group By c.Name