Q: days of certain month in pentaho report designer I'm using Pentaho Report Designer Version: 7.0.0.0-25.
I want to display all the days in a certain month. But month and year are parameters i.e, month and year are dynamically selected. I want to display all days of a selected month.
Please suggest me query in oracle or script in the Pentaho report designer. 

A: Hierarchical query helps.
Just setting default date format; you don't have to do that:
SQL> alter session set nls_date_format = 'dd.mm.yyyy';

Session altered.

Here's what you do need: input parameters are 


*

*month (par_month)

*year (par_year)


Month is converted into a two-digits value (using LPAD function) so that TO_DATE's format mask works correctly.
SQL> with test (start_date) as
  2    (select to_date(lpad(&par_month, 2, '0') || &par_year, 'mmyyyy')
  3     from dual
  4    )
  5  select start_date + level - 1 datum
  6  from test
  7  connect by level <= to_number(to_char(last_day(start_date), 'dd'));
Enter value for par_month: 2
Enter value for par_year: 2019
old   2:   (select to_date(lpad(&par_month, 2, '0') || &par_year, 'mmyyyy')
new   2:   (select to_date(lpad(2, 2, '0') || 2019, 'mmyyyy')

DATUM
----------
01.02.2019
02.02.2019
03.02.2019
04.02.2019
05.02.2019
06.02.2019
07.02.2019
08.02.2019
09.02.2019
10.02.2019
11.02.2019
12.02.2019
13.02.2019
14.02.2019
15.02.2019
16.02.2019
17.02.2019
18.02.2019
19.02.2019
20.02.2019
21.02.2019
22.02.2019
23.02.2019
24.02.2019
25.02.2019
26.02.2019
27.02.2019
28.02.2019

28 rows selected.

SQL>

