Oracle 11g Release 2

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CREATE TABLE source(customer VARCHAR2(100), YearMonth VARCHAR2(100), Revenue INT, Profit INT);
INSERT INTO source VALUES( 'a', '201801', 100,1)
1 rows affected

INSERT INTO source VALUES( 'a', '201801', 10,11)
1 rows affected

INSERT INTO source VALUES( 'b', '201802', 200,20)
1 rows affected

SELECT *
FROM  (SELECT * FROM source )s
PIVOT  ( SUM(Revenue) AS Revenue, SUM(Profit) AS Profit FOR (YearMonth) IN (201801, 201802)) s


CUSTOMER
201801_REVENUE
201801_PROFIT
201802_REVENUE
201802_PROFIT


a
110
12
null
null

b
null
null
200
20