WITH t AS
(
SELECT '00001' seq, '201812' yyyymm, 'A1' user_id, 10 plan, 8 rslt FROM dual
UNION ALL SELECT '00002', '201901', 'A1', 10, 10 FROM dual
UNION ALL SELECT '00003', '201902', 'A1', 10, 12 FROM dual
UNION ALL SELECT '00004', '201812', 'B1',  9, 10 FROM dual
UNION ALL SELECT '00005', '201901', 'B1',  9,  9 FROM dual
UNION ALL SELECT '00006', '201902', 'B1', 10,  9 FROM dual
UNION ALL SELECT '00007', '201903', 'B1',  5,  5 FROM dual
UNION ALL SELECT '00008', '201812', 'C1', 10,  9 FROM dual
UNION ALL SELECT '00009', '201901', 'C1',  9, 10 FROM dual
UNION ALL SELECT '00010', '201902', 'C1', 10, 10 FROM dual
)
SELECT user_id
     , NVL(SUM(DECODE(yyyymm, '201812', plan)), 0) p_201812
     , NVL(SUM(DECODE(yyyymm, '201812', rslt)), 0) r_201812
     , NVL(SUM(DECODE(yyyymm, '201901', plan)), 0) p_201901
     , NVL(SUM(DECODE(yyyymm, '201901', rslt)), 0) r_201901
     , NVL(SUM(DECODE(yyyymm, '201902', plan)), 0) p_201902
     , NVL(SUM(DECODE(yyyymm, '201902', rslt)), 0) r_201902
     , NVL(SUM(DECODE(yyyymm, '201903', plan)), 0) p_201903
     , NVL(SUM(DECODE(yyyymm, '201903', rslt)), 0) r_201903
  FROM t
 WHERE yyyymm BETWEEN '201812' AND '201903'
 GROUP BY user_id
;

마농님 고맙습니다.