Using IW and MM in Oracle

Question

I\'m using IW for weekly result and MM for Monthly result. But I always get an error:

ORA-00979: not a GROUP BY expression
00979. 00000 -  \"not a GROUP BY e         


        

Answer 1

You have to group by the same expression you use in the SELECT clause.

So if you:

SELECT TRUNC(t.CREATE_TIME, 'MM') AS report_date,count(*) AS cnt_opened

... then you have to ...

GROUP BY TRUNC(t.CREATE_TIME,'MM')