Requirements: list each type corresponding period all the years,
Data sources:

 
SELECT '2020-01' STATRDATE, '2020-12' ENDDATE, type '1' JOBACTIVITY FROM DUAL 
UNION ALL 
SELECT '2020-06' STATRDATE NVL (NULL, TO_CHAR (SYSDATE, 'YYYY - MM)) ENDDATE,' type 2 JOBACTIVITY FROM DUAL 

CodePudding user response:

Expect the result is what kind of list