You want UNISTR
(and, maybe, CAST
it to a VARCHAR2
). If you have the table:
CREATE TABLE person ( first_name, id ) AS
SELECT 'A', 1 FROM DUAL UNION ALL
SELECT CAST( UNISTR( '200D' ) AS VARCHAR2(20) ), 1 FROM DUAL;
Then the output from your query:
select first_name,
asciistr(first_name)
from person
where id = 1
Is:
FIRST_NAME | ASCIISTR(FIRST_NAME)
:--------- | :-------------------
A | A
? | 200D
db<>fiddle here
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…