Oracle xmlagg get correct output - sql

Question

I'm trying to do a dynamic pivot for some columns in a table. Normally, it goes smoothly with a listagg but in this case, since the resulting variable was greater than 3K characters, I had to go with xmlagg. However, I'm not able to get the output as
'COLUMN' as "COLUMN"
so I can then pivot the columns just I'm used to do with listagg.
SELECT
rtrim(XMLAGG(xmlelement(e, ''''
|| agr_name
|| ''' as "'
|| agr_name
|| '"', ', ').extract('//text()')
ORDER BY
agr_name
).getclobval(), ', ') agr_name
FROM
(
SELECT DISTINCT
agr_name
FROM
dat_skills
);
What I'm getting instead is
'COLUMN; as "COLUMN;,

Answer 1

Use xmlcast - it will solve several of your problems. I don't have your table, but here is how it works on a different one:
SELECT
rtrim(xmlcast(XMLAGG(xmlelement(e, ''''
|| object_type
|| ''' as "'
|| object_type
|| '"', ', ')
ORDER BY
object_type) as clob), ', ')
object_type
FROM
(
SELECT DISTINCT
object_type
FROM
user_objects
);
OBJECT_TYPE
--------------------------------------------------------------------------------
'FUNCTION' as "FUNCTION", 'INDEX' as "INDEX", 'LIBRARY' as "LIBRARY", 'LOB' as "
LOB", 'PROCEDURE' as "PROCEDURE", 'SEQUENCE' as "SEQUENCE", 'TABLE' as "TABLE",
'TYPE' as "TYPE", 'TYPE BODY' as "TYPE BODY", 'VIEW' as "VIEW"
You no longer need to extract text (cast as CLOB does that already), you don't need to worry about escaping and unescaping, and the result is a CLOB as you need it to be.

Answer 2

Include call to UTL_I18N.unescape_reference:
SELECT UTL_I18N.unescape_reference (
XMLAGG (XMLELEMENT (
e,
'''' || agr_name || ''' as "' || agr_name || '"',
', ').EXTRACT ('//text()')
ORDER BY agr_name).getclobval ()) agr_name
FROM (SELECT DISTINCT agr_name
FROM dat_skills);
With:
SQL> SELECT UTL_I18N.unescape_reference (
2 XMLAGG (XMLELEMENT (
3 e,
4 '''' || agr_name || ''' as "' || agr_name || '"',
5 ', ').EXTRACT ('//text()')
6 ORDER BY agr_name).getclobval ()) agr_name
7 FROM (SELECT DISTINCT agr_name
8 FROM dat_skills);
AGR_NAME
--------------------------------------------------------------------------------
'ACCOUNTING' as "ACCOUNTING", 'OPERATIONS' as "OPERATIONS", 'RESEARCH' as "RESEA
RCH", 'SALES' as "SALES",
Without:
SQL> SELECT
2 XMLAGG (XMLELEMENT (
3 e,
4 '''' || agr_name || ''' as "' || agr_name || '"',
5 ', ').EXTRACT ('//text()')
6 ORDER BY agr_name).getclobval () agr_name
7 FROM (SELECT DISTINCT dname agr_name
8 FROM dept);
AGR_NAME
--------------------------------------------------------------------------------
'ACCOUNTING' as "ACCOUNTING", 'OPERATIONS' as &quo
SQL>

Answer 3

Assuming you don't have any other characters that need unescaping, you can replace " and ' them with the actual quotes:
SELECT REPLACE(
REPLACE(
RTRIM(
XMLAGG(
xmlelement(
e,
'''' || agr_name || ''' as "' || agr_name || '"',
', '
).extract('//text()')
ORDER BY agr_name
).getclobval(),
', '
),
'"',
'"'
),
''',
''''
) AS agr_name
FROM (
SELECT DISTINCT
agr_name
FROM dat_skills
);
db<>fiddle here