SQL & PL/SQL

Data base version : Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi

Sample data :

WITH HIS_UNM_DATA

   AS (SELECT 'X' UNAME, TRUNC (SYSDATE - 1) DATA1 FROM DUAL

   UNION ALL

   SELECT 'X' UNAME, TRUNC (SYSDATE - 1) DATA1 FROM DUAL

   UNION ALL

   SELECT 'Y' UNAME, TRUNC (SYSDATE - 1) DATA1 FROM DUAL

   UNION ALL

   SELECT 'Z' UNAME, TRUNC (SYSDATE - 1) DATA1 FROM DUAL

   UNION ALL

   SELECT 'X' UNAME, TRUNC (SYSDATE) DATA1 FROM DUAL

   UNION ALL

   SELECT 'X' UNAME, TRUNC (SYSDATE) DATA1 FROM DUAL

   UNION ALL

   SELECT 'Y' UNAME, TRUNC (SYSDATE) DATA1 FROM DUAL

   UNION ALL

   SELECT 'Y' UNAME, TRUNC (SYSDATE) DATA1 FROM DUAL)

SELECT *

  FROM HIS_UNM_DATA;

Members log in to portal. Member login time will be captured into table. Need to generate report how many unique  members (based on uname) logged into portal like YTD.

Sample output.

I'm unable create the SQL for YTD_UNIQUE. Here on 5/16/2016 X,Y,Z were logged on. on 5/17/2016 only X,Y logged in...So YTD_UNIQUE was not increased.