Oracle SQL - Unpivot kind of logic but without hard coding

Question

I have table like below , there are many number of lines with debit/Credit string and respective amounts in a table , need to bring as expected table like in separate lines of each strings and its respective amounts , how can i achieve this, appreciate your help!

Debit String	Credit String	Debit Amount	Credit Amount
ING1	ING2	123	0
INT2	INT5	234	0

Expected Result is :-

String	Amount
ING1	123
INT2	234
ING2	0
INT5	0

Answer 1

Use UNPIVOT:

SELECT *
FROM   table_name
UNPIVOT (
  (string, amount) FOR type IN (
    (debit_string,  debit_amount ) AS 'D',
    (credit_string, credit_amount) AS 'C'
  )
);

Which, for the sample data:

CREATE TABLE table_name (Debit_String, Credit_String, Debit_Amount, Credit_Amount) AS
SELECT 'ING1', 'ING2', 123, 0 FROM DUAL UNION ALL
SELECT 'INT2', 'INT5', 234, 0 FROM DUAL;

Outputs:

TYPE	STRING	AMOUNT
D	ING1	123
C	ING2	0
D	INT2	234
C	INT5	0

db<>fiddle here