title: What's the difference between those 2 queries?
body: <p>Can you explain my why, in Oracle, this query returns something: </p>
  
  <pre><code>SELECT discounts.DiscountId,
         discounts.ShortDisplay,
         discounts.Display,
         discounts.Description,
         BillDetails.BillId,
         BillDetails.BillRow,
         BillDetails.BillId  AS BillIdTax,
         BillDetails.BillRow AS BillRowTax,
         BillDetails.FEDERAL_TAX_POSTPAID,
         BillDetails.TOTAL_RATE
  FROM   discounts
         INNER JOIN BillDetails
           ON discounts.DiscountId = BillDetails.DiscountId
         RIGHT OUTER JOIN BillDetailsTax
           ON BillDetails.BillId = BillDetailsTax.BillId
              AND BillDetails.BillRow = BillDetailsTax.BillRow
  WHERE  BillDetails.BillId = 602237 
  </code></pre>
  
  <p>And this one nothing : </p>
  
  <pre><code>SELECT discounts.DiscountId,
         discounts.ShortDisplay,
         discounts.Display,
         discounts.Description,
         BillDetails.BillId,
         BillDetails.BillRow,
         BillDetails.BillId  AS BillIdTax,
         BillDetails.BillRow AS BillRowTax,
         BillDetails.FEDERAL_TAX_POSTPAID,
         BillDetails.TOTAL_RATE
  FROM   BillDetails,
         BillDetailsTax BillDetails,
         discounts
  WHERE  BillDetails.BillRow = BillDetailsTax.BillRow(+)
         AND BillDetails.BillId = BillDetailsTax.BillId(+)
         AND BillDetails.DiscountId = discounts.DiscountId
         AND BillDetails.BillId = 602237 
  </code></pre>
  
  <p>Are those 2 queries not similar?</p>
  
  <p>Thank you!</p>