subquery eror and too many values using xmllagg - sql

Question

I have issue concatenating all of my data from many large tables. I asked question yesterday regarding this but unfortunately seems listagg is not good option. the link subquery return more than one row
I tried to use the xmllagg after listagg using to truncate is not possible with my version of oracle 12.0.1 , the first code as seen below is given subquery is returning more than one row...
SELECT rtrim(xmlagg(XMLELEMENT(e,table1.DESCRIPTION,',').EXTRACT ('//text()')
).GetClobVal(),',')
FROM table1
left join table2 on table1.app = table2.app
AND LANGUAGE = 2
GROUP BY table2.app
The second code one using another method is still saying too many values in first line
SELECT nvl(max(case when language = 2 then description end), 'NULL') key_event, rtrim(xmlagg(XMLELEMENT (e,table1.DESCRIPTION,',').EXTRACT ('//text()')
).GetClobVal(),',')
FROM table1
left join table2 on table1.app = table2.app
AND LANGUAGE = 2
GROUP BY table2.app
I have tested these 2 codes in this link dbfiddle and it was working. I want the result to be as this link
https://dbfiddle.uk/?rdbms=oracle_11.2&fiddle=40852eaeaa8f334f77364eef77ffbe68
I did get result testing it as small bit but when i try to use the full code just look at this code, it is not working please see the code and error below error :subquery return more than one row
SELECT
NVL(TO_CHAR(D_TRANS.TRANS), 'NULL') AS ID,
'HEADER'
, (SELECT L_APPLICATION.APPLICATION FROM L_APPLICATION L_APPLICATION WHERE LANGUAGE = 2 AND APPLICATION = D_TRANS.APPLICATION) AS CASE_TYPE
, NVL(TO_CHAR(D_TRANS.UNIT_IN_CHARGE), 'NULL') AS UNIT_IN_CHARGE
, NVL(TO_CHAR(D_TRANS.PERSON_IN_CHARGE), 'NULL') AS PERSON_IN_CHARGE
, NVL(TO_CHAR(D_TRANS.STATUS), 'NULL') AS CASE_STATUS
, NVL(TO_CHAR(D_TRANS.DEADLINE), 'NULL') AS INTERNAL_DEADLINE
(SELECT D_SYNERGI_CATEGORY.TRANS, nvl(max(case when language = 2 then description end), 'NULL') AS ADE , rtrim(xmlagg(XMLELEMENT (e,L_CASE_CATEGORY.DESCRIPTION,',').EXTRACT('//text()')
).GetClobVal(),',')
FROM L_CASE_CATEGORY
left join D_SYNERGI_CATEGORY on D_SYNERGI_CATEGORY.CASE_CATEGORY = L_CASE_CATEGORY.CASE_CATEGORY
GROUP BY D_SYNERGI_CATEGORY.TRANS
)
)
FROM D_TRANS
FULL OUTER JOIN D_SPILL
ON D_TRANS.TRANS=D_SPILL.TRANS
ORDER BY D_TRANS.TRANS DESC;
When I tested this small bit of this code below it is working.
(SELECT D_SYNERGI_CATEGORY.TRANS, nvl(max(case when language = 2 then description end), 'NULL') AS ADE , rtrim(xmlagg(XMLELEMENT(e,L_CASE_CATEGORY.DESCRIPTION,',').EXTRACT('//text()')
).GetClobVal(),',')
FROM L_CASE_CATEGORY
left join D_SYNERGI_CATEGORY on D_SYNERGI_CATEGORY.CASE_CATEGORY = L_CASE_CATEGORY.CASE_CATEGORY
GROUP BY D_SYNERGI_CATEGORY.TRANS
)
I am not expert in Oracle. Any suggestion ?

Answer 1

Combination of xmlagg and xQuery, it's not simple.
select xmlquery('distinct-values(//text())' passing x returning content).getclobVal(),data_type from (
select xmlelement(root, xmlagg(XMLELEMENT(e,table_name,','))) x ,data_type
from user_tab_cols where data_type in ('VARCHAR2','NUMBER')
group by data_type
)
And for you purpose it should look like this
select
app, key_event,
xmlquery('distinct-values(//text())' passing xmldoc returning content).getclobVal()
from
(select
t2.app,
coalesce(max(case when language = 2 then description end),
max(case when language = 12 then description end),
max(case when language = 27 then description end),
'NULL') key_event,
XMLELEMENT(root, xmlagg(XMLELEMENT(e, description, ','))
) xmldoc
from
table2 t2
left join
table1 t1 on t1.app = t2.app
group by
trans, t2.app
order by trans);
if you will decompose this query you will see how its work.
xquery distinct-values syntax
xmlquery syntax

Answer 2

with REGEXP_REPLACE we can make deduplication. Check this:
select t2.app,
coalesce(max(case when language = 2 then description end),
max(case when language = 12 then description end),
max(case when language = 27 then description end),
'NULL') key_event,
REGEXP_REPLACE(listagg(description, ',') within group (order by t1.description, t1.language), '([^,]+)(,\1)+', '\1') list
from table2 t2
left join table1 t1 on t1.app = t2.app
group by trans, t2.app
order by trans, trans;