ORA-00904: invalid identifier in subquery (in select clause) - sql

Question

I have a subquery that needs to use a value from the outer query. It fails because of the notorious "subquery in Oracle can't access a value from a parent query more than two level deeper" issue.
However, I can't figure out how to re-write it. Most examples on the web are for when the subquery is in the WHERE clause; mine is in the SELECT clause.
Help anyone?
select agre.*, agre.orga_ky,
orga.NAME_LA_LB as orga_name,
pers.LAST_NAME_LA_LB as SIGNATORY_ORGA__LASTNAME, pers.FIRST_NAME_LA_LB as SIGNATORY_ORGA_FIRSTNAME,
upper(pers.LAST_NAME_LA_LB) || ' ' || pers.FIRST_NAME_LA_LB as SIGNATORY_ORGA_FULLNAME,
-- Get the most current agreement for this orga and compare it with this row to find out if this row is current or expired
CASE WHEN (
SELECT AGRE_KY
FROM (
SELECT a.AGRE_KY
FROM T_AGREEMENT a
WHERE a.ORGA_KY = agre.orga_ky -- fail!!! ORA-00904: invalid identifier
ORDER BY a.REC_CREATION_DT DESC
)
WHERE ROWNUM = 1
) = agre.agre_ky THEN 'Current' ELSE 'Expired' END as agreement_status
from T_AGREEMENT agre
left outer join T_ORGANIZATION orga on agre.orga_ky = orga.orga_ky
left outer join T_PERSON pers on agre.SIGNATORY_ORGA_PERS_KY = pers.pers_ky
;

Answer 1

You can try using the row_number window function without the sub-query and check if it returns the expected result.
select agre.*, agre.orga_ky,
orga.NAME_LA_LB as orga_name,
pers.LAST_NAME_LA_LB as SIGNATORY_ORGA__LASTNAME, pers.FIRST_NAME_LA_LB as SIGNATORY_ORGA_FIRSTNAME,
upper(pers.LAST_NAME_LA_LB) || ' ' || pers.FIRST_NAME_LA_LB as SIGNATORY_ORGA_FULLNAME,
-- Get the most current agreement for this orga and compare it with this row to find out if this row is current or expired
CASE WHEN row_number() over(partition by agre.orga_ky order by agre.REC_CREATION_DT desc)
----------------^^^^^^^^^^^^ change the partitioning column per your requirement
= 1 THEN 'CURRENT'
ELSE 'EXPIRED' END as agreement_status
from T_AGREEMENT agre
left outer join T_ORGANIZATION orga on agre.orga_ky = orga.orga_ky
left outer join T_PERSON pers on agre.SIGNATORY_ORGA_PERS_KY = pers.pers_ky