Oracle SQL - 使用重复节点从XML中提取clob值

Question

I am attempting to run SQL on a table (called test_xml with a column xml_data [data type xmltype]). The column contains xml with repeating nodes ( test_3 ). The following statement runs successfully when the node contains data of a non clob size:

SELECT 
   extractvalue (Value (wl), '*/test_3')
      FROM test_xml
         , TABLE (xmlsequence (extract (xml_data, '*/record'))) wl

but fails when test_3 node contains a lot of data:

ORA-01706: user function result value was too large

I amended my query:

SELECT 
   extractvalue(Value (wl), '*/test_3').getClobVal()
      FROM test_xml
         , TABLE (xmlsequence (extract (xml_data, '*/record'))) wl

but this fails with:

ORA-22806: not an object or REF

Answer 1

This was resolved via a response received on Oracle Forums:

See Forum Post

From Oracle release 11.2.0.2:

SELECT x.*
FROM test_xml t
   , XMLTable(
       '/*/record'
       passing t.xml_data
       columns
         test_3  clob path 'test_3'
     ) x
;

My database version is 10.2.0.4 hence the following 'trick' is required:

SELECT dbms_xmlgen.convert(x.test_3.getClobVal(), 1) as test_3
FROM test_xml t
   , XMLTable(
       '/*/record'
       passing t.xml_data
       columns
         test_3  xmltype path 'test_3/text()'
     ) x
;

Thanks go to odie_63 for this