Flattening the xml data

Question

Hi,
I have the following XML loaded in the xmltype column.
<g1>
     <f1>A</f1>
     <g2>
          <f2>a</f2>
          <g3>
               <f3>1</f3>
               <f3>2</f3>
               <f3>3</f3>
          </g3>
     </g2>
     <g2>
          <f2>b</f2>
          <g3>
               <f3>5</f3>
               <f3>6</f3>
               <f3>7</f3>
          </g3>
     </g2>
</g1>
From the above xml, how to get the following result,
f1 f2 f3
===========================
A     a 1
A     a 2
A     a 3
A     b 5
A     b 6
A     b 7
Thanks.

Answer 1

SQL> var test varchar2(256)
SQL> --
SQL> begin
2 :test := '<g1>
3 <f1>A</f1>
4 <g2>
5 <f2>a</f2>
6 <g3>
7 <f3>1</f3>
8 <f3>2</f3>
9 <f3>3</f3>
10 </g3>
11 </g2>
12 <g2>
13 <f2>b</f2>
14 <g3>
15 <f3>5</f3>
16 <f3>6</f3>
17 <f3>7</f3>
18 </g3>
19 </g2>
20 </g1>';
21 end;
22 /
PL/SQL procedure successfully completed.
SQL> select xmltype(:test).extract('/*')
2 from dual
3 /
XMLTYPE(:TEST).EXTRACT('/*')
<g1>
<f1>A</f1>
<g2>
<f2>a</f2>
<g3>
<f3>1</f3>
<f3>2</f3>
<f3>3</f3>
</g3>
</g2>
<g2>
<f2>b</f2>
<g3>
<f3>5</f3>
<f3>6</f3>
<f3>7</f3>
</g3>
</g2>
</g1>
SQL> column F1 format A4
SQL> column F2 format A4
SQL> column F3 format A4
SQL> --
SQL> select extractvalue(xml,'/g1/f1') F1,
2 extractvalue(value(g2),'/g2/f2') F2,
3 extractValue(value(f3),'/f3') F3
4 from (select xmltype(:test) as xml from dual),
5 table (xmlsequence(extract(xml,'/g1/g2'))) g2,
6 table (xmlsequence(extract(value(g2),'/g2/g3/f3'))) f3
7 /
F1 F2 F3
A a 1
A a 2
A a 3
A b 5
A b 6
A b 7
6 rows selected.