SELECT 1 ID,'1001' usercode,'2013-03-05' updatecode FROM dual UNION ALL

SELECT 2,'1002','2014-03-05' FROM dual UNION ALL 

SELECT 3,'1001','2014-03-05' FROM dual UNION ALL 

SELECT 4,'1005','2014-03-01' FROM dual ),

 b AS(

SELECT 1 ID,'1003' usercode,'2014-03-05' createdate FROM dual UNION ALL

SELECT 2,'1002','2014-03-05' FROM dual UNION ALL 

SELECT 3,'1004','2014-03-05' FROM dual UNION ALL 

SELECT 4,'1005','2014-03-05' FROM dual UNION ALL 

SELECT 5,'1005','2014-03-05' FROM dual )

SELECT DECODE(C.USERCODE, NULL, D.USERCODE, C.USERCODE),

       DECODE(C.ANUM, NULL, 0, C.ANUM),

       DECODE(D.BNUM, NULL, 0, D.BNUM)

  FROM ((SELECT USERCODE, COUNT(1) ANUM FROM A GROUP BY USERCODE) C FULL JOIN

        (SELECT USERCODE, COUNT(1) BNUM FROM B GROUP BY USERCODE) D ON

        C.USERCODE = D.USERCODE)

 ORDER BY DECODE(C.USERCODE, NULL, D.USERCODE, C.USERCODE)

DECODE(C.USERCODE,NULL,D.USERC DECODE(C.ANUM,NULL,0,C.ANUM) DECODE(D.BNUM,NULL,0,D.BNUM)

------------------------------ ---------------------------- ----------------------------

1001                                                      2                            0

1002                                                      1                            1

1003                                                      0                            1

1004                                                      0