oracle XML to Database table - sql

Question

I have XML like this . I am unable to parse it into a table
<REQMST>
<ROW>
<REQ_ID>668 </REQ_ID>
<RequestDetails>
<REQ_DTL_ID>845</REQ_DTL_ID>
<INTERFACE_REFNUM>1</INTERFACE_REFNUM>
</RequestDetails>
<RequestDetails>
<REQ_DTL_ID>846</REQ_DTL_ID>
<INTERFACE_REFNUM>2</INTERFACE_REFNUM>
</RequestDetails>
</ROW>
</REQMST>
I am trying to parse it into table using
select *
FROM XMLTABLE('/REQMST/ROW'
PASSING
xmltype('
<REQMST>
<ROW>
<REQ_ID>668 </REQ_ID>
<RequestDetails>
<REQ_DTL_ID>845</REQ_DTL_ID>
<INTERFACE_REFNUM>1</INTERFACE_REFNUM>
</RequestDetails>
<RequestDetails>
<REQ_DTL_ID>846</REQ_DTL_ID>
<INTERFACE_REFNUM>2</INTERFACE_REFNUM>
</RequestDetails>
</ROW>
</REQMST>')
COLUMNS
--describe columns and path to them:
REQ_ID varchar2(20) PATH './REQ_ID',
REQ_DTL_ID varchar2(20) PATH './RequestDetails/REQ_DTL_ID',
INTERFACE_REFNUM varchar2(20) PATH './RequestDetails/INTERFACE_REFNUM'
) xmlt
;
I am getting error ORA-19279: XPTY0004 - XQuery dynamic type mismatch: expected singleton sequence - got multi-item sequence
it works if there is only one RequestDetails

Answer 1

You need to go one more level down to get the details from RequestDetails tag using the same technique as parent.
Used column name xml to get the xml as xmltype column and then use xmltable on it to get the further details:
Try this:
select xmlt.req_id, x.REQ_DTL_ID, x.INTERFACE_REFNUM
FROM XMLTABLE('/REQMST/ROW'
PASSING
xmltype('
<REQMST>
<ROW>
<REQ_ID>668 </REQ_ID>
<RequestDetails>
<REQ_DTL_ID>845</REQ_DTL_ID>
<INTERFACE_REFNUM>1</INTERFACE_REFNUM>
</RequestDetails>
<RequestDetails>
<REQ_DTL_ID>846</REQ_DTL_ID>
<INTERFACE_REFNUM>2</INTERFACE_REFNUM>
</RequestDetails>
</ROW>
</REQMST>')
COLUMNS
--describe columns and path to them:
REQ_ID varchar2(20) PATH 'REQ_ID',
xml xmltype PATH 'RequestDetails'
) xmlt, xmltable('/RequestDetails'
passing xmlt.xml
columns
REQ_DTL_ID varchar2(20) PATH 'REQ_DTL_ID',
INTERFACE_REFNUM varchar2(20) PATH 'INTERFACE_REFNUM'
) x;
Produces:
REQ_ID REQ_DTL_ID INTERFACE_REFNUM
668 845 1
668 846 2