Oracle 21c

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create table xtable(serial_no, prov_header) as
select 123456, 'Some text' || chr(10) || 'with line break' from dual;
1 rows affected

SELECT '"SERIAL_NO"<Sep>"PROV_HEADER"' FROM DUAL
UNION ALL
SELECT '"' ||SERIAL_NO|| '"<Sep>"'
||REPLACE(REPLACE(REPLACE(SUBSTR(PROV_HEADER,1,2000), CHR(10), ''), CHR(34),
'inchORspace'), CHR(44), '')|| '"' 
FROM XTABLE;


'"SERIAL_NO"<SEP>"PROV_HEADER"'


"SERIAL_NO"<Sep>"PROV_HEADER"

"123456"<Sep>"Some textwith line break"


SELECT '"SERIAL_NO"<Sep>"PROV_HEADER"' FROM DUAL
UNION ALL
SELECT '"' ||SERIAL_NO|| '"<Sep>"'
||REPLACE(REPLACE(REPLACE(SUBSTR(PROV_HEADER,1,2000), CHR(10), ''), CHR(34),
'inchORspace'), CHR(44), '')|| '"' 
FROM XTABLE 
ORDER BY SERIAL_NO;
ORA-00904: "SERIAL_NO": invalid identifier

SELECT RESULT
FROM (
  SELECT 0 AS ORD, NULL AS SERIAL_NO,
    '"SERIAL_NO"<Sep>"PROV_HEADER"' AS RESULT
  FROM DUAL
  UNION ALL
  SELECT 1 AS ORD, SERIAL_NO,
    '"' ||SERIAL_NO|| '"<Sep>"'
      ||REPLACE(REPLACE(REPLACE(SUBSTR(PROV_HEADER,1,2000), CHR(10), ''), CHR(34),
      'inchORspace'), CHR(44), '')|| '"'
  FROM XTABLE
)
ORDER BY ORD, SERIAL_NO;


RESULT


"SERIAL_NO"<Sep>"PROV_HEADER"

"123456"<Sep>"Some textwith line break"


SELECT RESULT
FROM (
  SELECT NULL AS SERIAL_NO,
    '"SERIAL_NO"<Sep>"PROV_HEADER"' AS RESULT
  FROM DUAL
  UNION ALL
  SELECT SERIAL_NO,
    '"' ||SERIAL_NO|| '"<Sep>"'
      ||REPLACE(REPLACE(REPLACE(SUBSTR(PROV_HEADER,1,2000), CHR(10), ''), CHR(34),
      'inchORspace'), CHR(44), '')|| '"'
  FROM XTABLE
)
ORDER BY SERIAL_NO NULLS FIRST;


RESULT


"SERIAL_NO"<Sep>"PROV_HEADER"

"123456"<Sep>"Some textwith line break"