Oracle 21c

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CREATE TABLE table_name (Col1, Col2) AS
SELECT 100, 1 FROM DUAL UNION ALL
SELECT 100, 2 FROM DUAL UNION ALL
SELECT 100, 3 FROM DUAL UNION ALL
SELECT 100, 4 FROM DUAL;
4 rows affected

SELECT *
FROM   table_name
PIVOT (
  MAX(Col2)
  FOR Col2 IN (1 AS col2, 2 AS col3, 3 AS col4, 4 AS col5)
)


COL1
COL2
COL3
COL4
COL5


100
1
2
3
4


SELECT *
FROM   (
  SELECT t.*, ROW_NUMBER() OVER (PARTITION BY Col1 ORDER BY Col2) AS rn
  FROM   table_name t
)
PIVOT (
  MAX(Col2)
  FOR rn IN (
    1 AS col2,
    2 AS col3,
    3 AS col4,
    4 AS col5,
    5 AS col6,
    6 AS col7,
    7 AS col8,
    8 AS col9,
    9 AS col10,
    10 AS col11,
    11 AS col12,
    12 AS col13,
    13 AS col14,
    14 AS col15,
    15 AS col16
  )
)


COL1
COL2
COL3
COL4
COL5
COL6
COL7
COL8
COL9
COL10
COL11
COL12
COL13
COL14
COL15
COL16


100
1
2
3
4
null
null
null
null
null
null
null
null
null
null
null


SELECT Col1,
       MAX(CASE rn WHEN 1 THEN Col2 END) AS Col2,
       MAX(CASE rn WHEN 2 THEN Col2 END) AS Col3,
       MAX(CASE rn WHEN 3 THEN Col2 END) AS Col4,
       MAX(CASE rn WHEN 4 THEN Col2 END) AS Col5,
       MAX(CASE rn WHEN 5 THEN Col2 END) AS Col6,
       MAX(CASE rn WHEN 6 THEN Col2 END) AS Col7,
       MAX(CASE rn WHEN 7 THEN Col2 END) AS Col8,
       MAX(CASE rn WHEN 8 THEN Col2 END) AS Col9,
       MAX(CASE rn WHEN 9 THEN Col2 END) AS Col10,
       MAX(CASE rn WHEN 10 THEN Col2 END) AS Col11,
       MAX(CASE rn WHEN 11 THEN Col2 END) AS Col12,
       MAX(CASE rn WHEN 12 THEN Col2 END) AS Col13,
       MAX(CASE rn WHEN 13 THEN Col2 END) AS Col14,
       MAX(CASE rn WHEN 14 THEN Col2 END) AS Col15,
       MAX(CASE rn WHEN 15 THEN Col2 END) AS Col16
FROM   (
  SELECT t.*, ROW_NUMBER() OVER (PARTITION BY Col1 ORDER BY Col2) AS rn
  FROM   table_name t
)
GROUP BY Col1


COL1
COL2
COL3
COL4
COL5
COL6
COL7
COL8
COL9
COL10
COL11
COL12
COL13
COL14
COL15
COL16


100
1
2
3
4
null
null
null
null
null
null
null
null
null
null
null