How do i transpose and grouping in PL/SQL [ORACLE]

I have this table:

SELECT 
    USER, 
    DEP
FROM Table_1;

USER	DEP
USER1	DEP1
USER2	DEP2
USER3	DEP2
USER4	DEP3

But i want to transpose it and group user under DEP.

DEP1	DEP2	DEP3
USER1	USER2	USER4
USER3	NULL	NULL

What i have tried following pivot query.

SELECT *
FROM
( 
    SELECT 
        USER,
        DEP
    FROM Table_1
) AS NewTable
PIVOT
(
  MAX(USER)
  FOR DEP IN ([DEP1],[DEP2],[DEP3])
) AS pvt;

The output is: 00933. 00000 - "SQL command not properly ended".

How do i use PIVOT properly?

Answer

You can give each DEP type a row number and then pivot:

SELECT dep1,
       dep2,
       dep3
FROM   (
  SELECT "USER",
         dep,
         ROW_NUMBER() OVER ( PARTITION BY dep ORDER BY ROWNUM ) AS rn
  FROM   table_1
)
PIVOT (
  MAX( "USER" )
  FOR DEP IN (
    'DEP1' AS dep1,
    'DEP2' AS dep2,
    'DEP3' AS dep3
  )
)
ORDER BY rn

Which, for the sample data:

CREATE TABLE table_1 ( "USER", DEP ) AS
SELECT 'USER1', 'DEP1' FROM DUAL UNION ALL
SELECT 'USER2', 'DEP2' FROM DUAL UNION ALL
SELECT 'USER3', 'DEP2' FROM DUAL UNION ALL
SELECT 'USER4', 'DEP3' FROM DUAL;

Outputs:

DEP1  | DEP2  | DEP3 
:---- | :---- | :----
USER1 | USER2 | USER4
null  | USER3 | null 

db<>fiddle here