Xpath expression to read contents

Question

requesting to help to write an xpath expression to read contents of the below xml.
i/p doc
<transaction tid='00000000000000001852' ts='2012-05-10 08:43:15.000631' ops='2' commitTs='2012-05-10 08:43:15.000631'>
<operation table='INTEREST_ACCRUAL_TERMS' type='UPDATE_FIELDCOMP' pos='00000000000000001852' numCols='20'>
<col name='INTEREST_ACCRUAL_TERMS_ID' index='0'>
<before missing='true'/>
<after><![CDATA[23287]]></after>
</col>
<col name='INSTRUMENT_ID' index='1'>
<before missing='true'/>
<after><![CDATA[23287]]></after>
</col>
<col name='SWAP_LEG_ID' index='2'>
<before missing='true'/>
<after isNull='true'/>
</col>
<col name='PAYMNT_BUS_DAY_CONVEN_CD' index='3'>
<before missing='true'/>
<after isNull='true'/>
</col>
<col name='ACCRUAL_CALC_METHOD_CD' index='4'>
<before missing='true'/>
<after><![CDATA[M]]></after>
</col>
</operation>
<operation table='INTEREST_ACCRUAL_TERMS' type='UPDATE_FIELDCOMP' pos='00000000000000002255' numCols='20'>
<col name='INTEREST_ACCRUAL_TERMS_ID' index='0'>
<before missing='true'/>
<after><![CDATA[23288]]></after>
</col>
<col name='INSTRUMENT_ID' index='1'>
<before missing='true'/>
<after><![CDATA[23288]]></after>
</col>
<col name='SWAP_LEG_ID' index='2'>
<before missing='true'/>
<after isNull='true'/>
</col>
<col name='PAYMNT_BUS_DAY_CONVEN_CD' index='3'>
<before missing='true'/>
<after isNull='true'/>
</col>
<col name='ACCRUAL_CALC_METHOD_CD' index='4'>
<before missing='true'/>
<after><![CDATA[M]]></after>
</col>
</operation>
</transaction>
Expecting result from the xml doc:
<xml>
<INTEREST_ACCRUAL_TERMS_ID>23287</INTEREST_ACCRUAL_TERMS_ID>
<INSTRUMENT_ID>23287</INSTRUMENT_ID>
<SWAP_LEG_ID/>
<PAYMNT_BUS_DAY_CONVEN_CD/
<ACCRUAL_CALC_METHOD_CD> M</ACCRUAL_CALC_METHOD_CD>
</xml>
<xml>
<INTEREST_ACCRUAL_TERMS_ID>23288</INTEREST_ACCRUAL_TERMS_ID>
<INSTRUMENT_ID>23288</INSTRUMENT_ID>
<SWAP_LEG_ID/>
<PAYMNT_BUS_DAY_CONVEN_CD/
<ACCRUAL_CALC_METHOD_CD> M</ACCRUAL_CALC_METHOD_CD>
</xml>

Answer 1

Assuming the document resides in an XMLType table :
SQL> select xmlserialize(document
  2           x.result_doc
  3           as clob indent -- for display purpose only
  4         )
  5  from tmp_xml t
  6     , xmltable(
  7        'for $i in /transaction/operation
  8         return <xml>
  9         {
10           for $j in $i/col
11           order by xs:integer($j/@index)
12           return element { $j/@name } { data($j/after) }
13         }
14         </xml>'
15        passing t.object_value
16        columns result_doc xmltype path '.'
17       ) x
18  ;
XMLSERIALIZE(DOCUMENTX.RESULT_
<xml>
  <INTEREST_ACCRUAL_TERMS_ID>23287</INTEREST_ACCRUAL_TERMS_ID>
  <INSTRUMENT_ID>23287</INSTRUMENT_ID>
  <SWAP_LEG_ID/>
  <PAYMNT_BUS_DAY_CONVEN_CD/>
  <ACCRUAL_CALC_METHOD_CD>M</ACCRUAL_CALC_METHOD_CD>
</xml>
<xml>
  <INTEREST_ACCRUAL_TERMS_ID>23288</INTEREST_ACCRUAL_TERMS_ID>
  <INSTRUMENT_ID>23288</INSTRUMENT_ID>
  <SWAP_LEG_ID/>
  <PAYMNT_BUS_DAY_CONVEN_CD/>
  <ACCRUAL_CALC_METHOD_CD>M</ACCRUAL_CALC_METHOD_CD>
</xml>
Please post more specific details if that's not what you want (database version, origin of the doc etc.).