Show data from table even if there is no data!! Oracle

Question

I have a query which shows count of messages received based on dates. For Eg:

1 | 1-May-2012 
3 | 3-May-2012 
4 | 6-May-2012 
7 | 7-May-2012 
9 | 9-May-2012 
5 |         


        

Answer 1

You don't need a separate table for this, you can create what you need in the query. This works for May:

WITH month_may AS (
    select to_date('2012-05-01', 'yyyy-mm-dd') + level - 1 AS the_date
    from dual
    connect by level < 31
)
SELECT *
  FROM month_may mm
  LEFT JOIN mytable t ON t.some_date = mm.the_date

The date range will depend on how exactly you want to do this and what your range is.