How to get node number in SQL/XML?

[zukes1966]

I have following XML in /tmp/dta.xml *stfm file:

<group>
  <node>A</node>
  <data>
     <a>a1</a>
     <b>b1</b>
  </data>
  <data>
     <a>a2</a>
     <b>b2</b>
  </data>
</group>
<group>
  <node>A</node>
  <data>
     <a>a1</a>
     <b>b1</b>
  </data>
  <data>
     <a>a2</a>
     <b>b2</b>
  </data>
  <data>
     <a>a3</a>
     <b>b3</b>
  </data>

</group>

I need to know for each node belong pair a and b.

I prepare somethig like this:

select xmldta.*
from xmltable ('/group' passing
           xmlparse (document get_xml_file('/tmp/dta.txt') columns
                               seq for ordinarlity,
                               a char(5) path 'data/a',
                               b char(5) path 'data/b'
                              )

I receive
1 a1 b1
2 a2 b2
3 a1 b1
4 a2 b2
5 a3 b3

but I need also "node" number. It means

node
1 1 a1 b1
1 2 a2 b2
2 3 a1 b1
2 4 a2 b2
2 5 a3 b3

Element <node> can have the same value.
Do you have any idea?

[zukes1966]

The use of

[fn:position]

gives very promising results. I describe whole solution when I finish.

[jamief]

Thanks for keep us in the loop!!!

[mjhaston]

Does row_number help?

SELECT
XMLELEMENT(NAME "LineItem", xmlattributes(row_number() over (order by olprdc) as "lineItemNumber"),
XMLFOREST(
trim(olprdc) as "Product",
oloqty as "Quantity",
olsalp as "ExtendedPrice"
)
) as lineItem
FROM srbbspiql1
where olcorn = '3102102'



Results in:

    <LineItem lineItemNumber="1">
        <Product>ANDM 026743N</Product>
        <Quantity>1.000</Quantity>
        <ExtendedPrice>6530.0000</ExtendedPrice>
    </LineItem>
    <LineItem lineItemNumber="2">
        <Product>ANDM 027955N</Product>
        <Quantity>1.000</Quantity>
        <ExtendedPrice>18480.0000</ExtendedPrice>
    </LineItem>
    <LineItem lineItemNumber="3">
        <Product>BAYM 026379N</Product>
        <Quantity>2.000</Quantity>
        <ExtendedPrice>5000.0000</ExtendedPrice>
    </LineItem>
    <LineItem lineItemNumber="4">
        <Product>BETM 026009N</Product>
        <Quantity>1.000</Quantity>
        <ExtendedPrice>11530.0000</ExtendedPrice>
    </LineItem>

[zukes1966]

You described the opposite situation (encapsulation) I need to do it during parsing. But as I wrote I have a solution but I will describe it when I finish the project.