How to convert CLOB to VARCHAR2 in Oracle - oracle

Question

I am trying to transform a data that has been saved in a table as CLOB to varchar2. When the query is executed the value that is returned is still a CLOB. What can I be doing wrong when it comes to building the query?
I tried
select l.user_id, l.login, l.is_active, l.is_locked,
(SELECT rtrim(xmlagg(xmlelement(e,lav.ATTR_VALUE,',').extract('//text()') order by TO_CHAR(lav.ATTR_VALUE)).getClobVal,',')
FROM LOGIN l1,LOGIN_ATTRIBUTES la,LOGIN_ATTRIBUTE_VALUES lav
WHERE l1.LOGIN_ID = la.LOGIN_ID AND la.ID = lav.LOGIN_ATTRIBUTE_ID AND la.NAME = 'email') as EMAIL
from IAMUSER.LOGIN l
left join IAMUSER.MANAGED_SYS ms on ms.managed_sys_id = l.managed_sys_id
where l.managed_sys_id = 'MOODLE' and login = 'ex392310'
Results:
USER_ID |LOGIN |IS_ACTIVE|IS_LOCKED|EMAIL |
--------------------------------+--------+---------+---------+------+
8a8c9321799d403d01799e401527011c|ex392310|Y |N |[CLOB]|

Answer 1

Change getClobVal() to getStringVal():
select l.user_id,
l.login,
l.is_active,
l.is_locked,
( SELECT rtrim(
xmlagg(
xmlelement(e,lav.ATTR_VALUE,',').extract('//text()')
order by TO_CHAR(lav.ATTR_VALUE)
).getStringVal(),
','
)
FROM LOGIN l1
INNER JOIN LOGIN_ATTRIBUTES la
ON (l1.LOGIN_ID = la.LOGIN_ID)
INNER JOIN LOGIN_ATTRIBUTE_VALUES lav
ON (la.ID = lav.LOGIN_ATTRIBUTE_ID)
WHERE la.NAME = 'email'
) as EMAIL
from IAMUSER.LOGIN l
left join IAMUSER.MANAGED_SYS ms
on ms.managed_sys_id = l.managed_sys_id
where l.managed_sys_id = 'MOODLE'
and login = 'ex392310'
Or, use LISTAGG:
select l.user_id,
l.login,
l.is_active,
l.is_locked,
( SELECT LISTAGG(lav.ATTR_VALUE,',')
WITHIN GROUP (ORDER BY TO_CHAR(lav.ATTR_VALUE))
FROM LOGIN l1
INNER JOIN LOGIN_ATTRIBUTES la
ON (l1.LOGIN_ID = la.LOGIN_ID)
INNER JOIN LOGIN_ATTRIBUTE_VALUES lav
ON (la.ID = lav.LOGIN_ATTRIBUTE_ID)
WHERE la.NAME = 'email'
) as EMAIL
from IAMUSER.LOGIN l
left join IAMUSER.MANAGED_SYS ms
on ms.managed_sys_id = l.managed_sys_id
where l.managed_sys_id = 'MOODLE'
and login = 'ex392310'