How to load a XML file into a table

Question

Hi,
I've been working on Oracle for many years but for the first time I was asked to load a XML file into a table.
As an example, I've found this on the web, but it doesn't work
Can someone tell me why? I hoped this example could help me.
the file acct.xml is this:
<?xml version="1.0"?>
<ACCOUNT_HEADER_ACK>
<HEADER>
<STATUS_CODE>100</STATUS_CODE>
<STATUS_REMARKS>check</STATUS_REMARKS>
</HEADER>
<DETAILS>
<DETAIL>
<SEGMENT_NUMBER>2</SEGMENT_NUMBER>
<REMARKS>rp polytechnic</REMARKS>
</DETAIL>
<DETAIL>
<SEGMENT_NUMBER>3</SEGMENT_NUMBER>
<REMARKS>rp polytechnic administration</REMARKS>
</DETAIL>
<DETAIL>
<SEGMENT_NUMBER>4</SEGMENT_NUMBER>
<REMARKS>rp polytechnic finance</REMARKS>
</DETAIL>
<DETAIL>
<SEGMENT_NUMBER>5</SEGMENT_NUMBER>
<REMARKS>rp polytechnic logistics</REMARKS>
</DETAIL>
</DETAILS>
<HEADER>
<STATUS_CODE>500</STATUS_CODE>
<STATUS_REMARKS>process exception</STATUS_REMARKS>
</HEADER>
<DETAILS>
<DETAIL>
<SEGMENT_NUMBER>20</SEGMENT_NUMBER>
<REMARKS> base polytechnic</REMARKS>
</DETAIL>
<DETAIL>
<SEGMENT_NUMBER>30</SEGMENT_NUMBER>
</DETAIL>
<DETAIL>
<SEGMENT_NUMBER>40</SEGMENT_NUMBER>
<REMARKS> base polytechnic finance</REMARKS>
</DETAIL>
<DETAIL>
<SEGMENT_NUMBER>50</SEGMENT_NUMBER>
<REMARKS> base polytechnic logistics</REMARKS>
</DETAIL>
</DETAILS>
</ACCOUNT_HEADER_ACK>
For the two tags HEADER and DETAILS I have the table:
create table xxrp_acct_details(
status_code number,
status_remarks varchar2(100),
segment_number number,
remarks varchar2(100)
before I've created a
create directory test_dir as 'c:\esterno'; -- where I have my acct.xml
and after, can you give me a script for loading data by using XMLTABLE?
I've tried this but it doesn't work:
DECLARE
acct_doc xmltype := xmltype( bfilename('TEST_DIR','acct.xml'), nls_charset_id('AL32UTF8') );
BEGIN
insert into xxrp_acct_details (status_code, status_remarks, segment_number, remarks)
select x1.status_code,
        x1.status_remarks,
        x2.segment_number,
        x2.remarks
from xmltable(
  '/ACCOUNT_HEADER_ACK/HEADER'
  passing acct_doc
  columns header_no      for ordinality,
          status_code    number        path 'STATUS_CODE',
          status_remarks varchar2(100) path 'STATUS_REMARKS'
) x1,
xmltable(
  '$d/ACCOUNT_HEADER_ACK/DETAILS[$hn]/DETAIL'
  passing acct_doc as "d",
          x1.header_no as "hn"
  columns segment_number number        path 'SEGMENT_NUMBER',
          remarks        varchar2(100) path 'REMARKS'
) x2
END;
This should allow me to get something like this:
select * from xxrp_acct_details;
Statuscode status remarks segement remarks
100 check 2 rp polytechnic
100 check 3 rp polytechnic administration
100 check 4 rp polytechnic finance
100 check 5 rp polytechnic logistics
500 process exception 20 base polytechnic
500 process exception 30
500 process exception 40 base polytechnic finance
500 process exception 50 base polytechnic logistics
but I get:
Error report:
ORA-06550: line 19, column 11:
PL/SQL: ORA-00932: inconsistent datatypes: expected - got NUMBER
ORA-06550: line 4, column 2:
PL/SQL: SQL Statement ignored
06550. 00000 -  "line %s, column %s:\n%s"
*Cause:    Usually a PL/SQL compilation error.
and if I try to change the script without using the column HEADER_NO to keep track of the header rank inside the document:
DECLARE
acct_doc xmltype := xmltype( bfilename('TEST_DIR','acct.xml'), nls_charset_id('AL32UTF8') );
BEGIN
insert into xxrp_acct_details (status_code, status_remarks, segment_number, remarks)
select x1.status_code,
        x1.status_remarks,
        x2.segment_number,
        x2.remarks
from xmltable(
  '/ACCOUNT_HEADER_ACK/HEADER'
  passing acct_doc
  columns status_code    number        path 'STATUS_CODE',
          status_remarks varchar2(100) path 'STATUS_REMARKS'
) x1,
xmltable(
  '/ACCOUNT_HEADER_ACK/DETAILS'
  passing acct_doc
  columns segment_number number        path 'SEGMENT_NUMBER',
          remarks        varchar2(100) path 'REMARKS'
) x2
END;
I get this message:
Error report:
ORA-19114: error during parsing the XQuery expression: 
ORA-06550: line 1, column 13:
PLS-00201: identifier 'SYS.DBMS_XQUERYINT' must be declared
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored
ORA-06512: at line 4
19114. 00000 -  "error during parsing the XQuery expression: %s"
*Cause:    An error occurred during the parsing of the XQuery expression.
*Action:   Check the detailed error message for the possible causes.
My oracle version is 10gR2 Express Edition
I do need a script for loading xml files into a table as soon as possible, Give me please a simple example for understanding and that works on 10gR2 Express Edition
Thanks in advance!

Answer 1

The reason your first SQL statement
select x1.status_code,
        x1.status_remarks,
        x2.segment_number,
        x2.remarks
from xmltable(
  '/ACCOUNT_HEADER_ACK/HEADER'
  passing acct_doc
  columns header_no      for ordinality,
          status_code    number        path 'STATUS_CODE',
          status_remarks varchar2(100) path 'STATUS_REMARKS'
) x1,
xmltable(
  '$d/ACCOUNT_HEADER_ACK/DETAILS[$hn]/DETAIL'
  passing acct_doc as "d",
          x1.header_no as "hn"
  columns segment_number number        path 'SEGMENT_NUMBER',
          remarks        varchar2(100) path 'REMARKS'
) x2
returns the error you noticed
PL/SQL: ORA-00932: inconsistent datatypes: expected - got NUMBER
is because Oracle is expecting XML to be passed in.  At the moment I forget if it requires a certain format or not, but it is simply expecting the value to be wrapped in simple XML.
Your query actually runs as is on 11.1 as Oracle changed how that functionality worked when 11.1 was released.  Your query runs slowly, but it does run.
As you are dealing with groups, is there any way the input XML can be modified to be like
<ACCOUNT_HEADER_ACK>
<ACCOUNT_GROUP>
<HEADER>....</HEADER>
<DETAILS>....</DETAILS>
</ACCOUNT_GROUP>
  <ACCOUNT_GROUP>
  <HEADER>....</HEADER>
  <DETAILS>....</DETAILS>
  </ACCOUNT_GROUP>
</ACCOUNT_HEADER_ACK>
so that it is easier to associate a HEADER/DETAILS combination?  If so, it would make parsing the XML much easier.
Assuming the answer is no, here is one hack to accomplish your goal
select x1.status_code,
        x1.status_remarks,
        x3.segment_number,
        x3.remarks
from xmltable(
  '/ACCOUNT_HEADER_ACK/HEADER'
  passing acct_doc
  columns header_no      for ordinality,
          status_code    number        path 'STATUS_CODE',
          status_remarks varchar2(100) path 'STATUS_REMARKS'
) x1,
xmltable(
  '$d/ACCOUNT_HEADER_ACK/DETAILS'
  passing acct_doc as "d",
  columns detail_no      for ordinality,
          detail_xml     xmltype       path 'DETAIL'
) x2,
xmltable(
  'DETAIL'
  passing x2.detail_xml
  columns segment_number number        path 'SEGMENT_NUMBER',
          remarks        varchar2(100) path 'REMARKS') x3
WHERE x1.header_no = x2.detail_no;
This follows the approach you started with.  Table x1 creates a row for each HEADER node and table x2 creates a row for each DETAILS node.  It assumes there is always a one and only one association between the two.  I use table x3, which is joined to x2, to parse the many DETAIL nodes.  The WHERE clause then joins each header row to the corresponding details row and produces the eight rows you are seeking.
There is another approach that I know of, and that would be using XQuery within the XMLTable.  It should require using only one XMLTable but I would have to spend some time coming up with that solution and I can't recall whether restrictions exist in 10gR2 Express Edition compared to what can run in 10.2 Enterprise Edition for XQuery.