UNPIVOT in SQL

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SELECT 'welcome' col1,
       'to'      col2,
       'oracle'  col3,
       'class'   col4
FROM   dual;

---

SELECT * FROM (
            SELECT
                'welcome' col1,
                'to'      col2,
                'oracle'  col3,
                'class'   col4
            FROM
                dual)
UNPIVOT(column_val for column_name IN (col1,col2,col3,col4));

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SELECT
    *
FROM
    (
        SELECT
            ename,
            To_char(empno) empno,
            job
        FROM
            emp
    )
UNPIVOT ( column_val for column_name  IN ( ename,empno,job ));

---