How to generate the following XML

Question

Hi all,
I have 2 tables, demo_orders and demo_order_items (child)
how can I generate something like this :
<?xml version="1.0"?>
<ROWSET>
<ROW>
  <ORDER_ID>1</ORDER_ID>
  <CUSTOMER_ID>1</CUSTOMER_ID>
  <ORDER_TOTAL>1200</ORDER_TOTAL>
  <ORDER_TIMESTAMP>2009-01-16T16:20:09.000</ORDER_TIMESTAMP>
  <USER_ID>2</USER_ID>
  <ITEMS>
   <ITEMROW>
    <ORDER_ITEM_ID>1</ORDER_ITEM_ID>
    <ORDER_ID>1</ORDER_ID>
    <PRODUCT_ID>1</PRODUCT_ID>
    <UNIT_PRICE>1200</UNIT_PRICE>
    <QUANTITY>1</QUANTITY>
   </ITEMROW>
  </ITEMS>
</ROW>
<ROW>
  <ORDER_ID>2</ORDER_ID>
  <CUSTOMER_ID>2</CUSTOMER_ID>
  <ORDER_TOTAL>599</ORDER_TOTAL>
  <ORDER_TIMESTAMP>2009-01-11T16:20:09.000</ORDER_TIMESTAMP>
  <USER_ID>2</USER_ID>
  <ITEMS>
   <ITEMROW>
    <ORDER_ITEM_ID>2</ORDER_ITEM_ID>
    <ORDER_ID>2</ORDER_ID>
    <PRODUCT_ID>2</PRODUCT_ID>
    <UNIT_PRICE>199</UNIT_PRICE>
    <QUANTITY>1</QUANTITY>
   </ITEMROW>
   <ITEMROW>
    <ORDER_ITEM_ID>3</ORDER_ITEM_ID>
    <ORDER_ID>2</ORDER_ID>
    <PRODUCT_ID>8</PRODUCT_ID>
    <UNIT_PRICE>50</UNIT_PRICE>
    <QUANTITY>2</QUANTITY>
   </ITEMROW>
  </ITEMS>
</ROW>
</ROWSET>

Answer 1

Hi, I'm assuming that table columns have the same names as the xml elements in your example.
Try this:
SQL >select xmlelement("ROWSET",
  2                    xmlagg(xmlelement("ROW",xmlforest(order_id,
  3                                                      customer_id,
  4                                                      order_total,
  5                                                      to_char(order_timestamp,'yyyy-mm-dd"T"hh24:mi:ss.FF3') as "ORDER_TIMESTAMP",
  6                                                      user_id),
  7                                            xmlelement("ITEMS",(select
  8                                                               xmlagg(xmlelement("ITEMROW",xmlforest(order_item_id,
  9                                                                                                     order_id,
10                                                                                                     product_id,
11                                                                                                     unit_price,
12                                                                                                     quantity)
13                                                                                )
14                                                                     ) from demo_order_items i where i.order_id=o.order_id)
15                                                       )
16                                     )
17                          )
18                   ).extract('/*') as yourXML
19    from demo_orders o; 
YOURXML
<ROWSET>
  <ROW>
    <ORDER_ID>1</ORDER_ID>
    <CUSTOMER_ID>1</CUSTOMER_ID>
    <ORDER_TOTAL>1200</ORDER_TOTAL>
    <ORDER_TIMESTAMP>2009-12-28T10:19:01.464</ORDER_TIMESTAMP>
    <USER_ID>2</USER_ID>
    <ITEMS>
      <ITEMROW>
        <ORDER_ITEM_ID>1</ORDER_ITEM_ID>
        <ORDER_ID>1</ORDER_ID>
        <PRODUCT_ID>1</PRODUCT_ID>
        <UNIT_PRICE>1200</UNIT_PRICE>
        <QUANTITY>1</QUANTITY>
      </ITEMROW>
    </ITEMS>
  </ROW>
  <ROW>
    <ORDER_ID>2</ORDER_ID>
    <CUSTOMER_ID>2</CUSTOMER_ID>
    <ORDER_TOTAL>599</ORDER_TOTAL>
    <ORDER_TIMESTAMP>2009-12-28T10:19:01.464</ORDER_TIMESTAMP>
    <USER_ID>2</USER_ID>
    <ITEMS>
      <ITEMROW>
        <ORDER_ITEM_ID>2</ORDER_ITEM_ID>
        <ORDER_ID>2</ORDER_ID>
        <PRODUCT_ID>2</PRODUCT_ID>
        <UNIT_PRICE>199</UNIT_PRICE>
        <QUANTITY>1</QUANTITY>
      </ITEMROW>
      <ITEMROW>
        <ORDER_ITEM_ID>3</ORDER_ITEM_ID>
        <ORDER_ID>2</ORDER_ID>
        <PRODUCT_ID>8</PRODUCT_ID>
        <UNIT_PRICE>50</UNIT_PRICE>
        <QUANTITY>2</QUANTITY>
      </ITEMROW>
    </ITEMS>
  </ROW>
</ROWSET>The extract('/*') method it's only useful to get a pretty formatted output. Remove it in your production applications for better performances and space saving.
Max
[My Italian Oracle blog|http://oracleitalia.wordpress.com/2009/12/27/inviare-email-dal-db-utilizzando-utl_smtp/]