Invalid Date for my Procedure

Question

Hi Friends,
I have a procedure RTG_Rerun_mtd_negative(v_revdate in date).
When I run it:
SQL> exec rtg_rerun_mtd_negative('20-AUG-10');
BEGIN rtg_rerun_mtd_negative('20-AUG-10'); END;
ERROR at line 1:
ORA-01843: not a valid month
ORA-06512: at "APPS.RTG_RERUN_MTD_NEGATIVE", line 79
ORA-06512: at line 1How do I troubleshoot this please....
Thanks a lot,
Ms K

Answer 1

TO do a correct conversion from string into a date, you need to add the proper format mask and be aware of the environment variables.
Check out the next examples to see a few traps that can happen with your input string.
/*  current date ?/
SQL> select sysdate, TO_DATE ('20-AUG-10', 'DD-MON-YY') param from dual;
SYSDATE   PARAM
20-AUG-10 20-AUG-10
SQL>
/* seems to be identical. right?
Well yes. But what would happen if anyone enters 99 as the year? I would expect 1999.
SQL> alter session set nls_date_format = 'DD-MON-YYYY';
Session altered.
SQL>  select TO_DATE ('20-AUG-99', 'DD-MON-YY') param from dual;
PARAM
20-AUG-2099
/* better use RR as the format mask */
SQL> select TO_DATE ('20-AUG-99', 'DD-MON-RR') param from dual;
PARAM
20-AUG-1999
/+ still better you 4 digits for the year instead of 2
SQL> select TO_DATE ('20-AUG-99', 'DD-MON-RRRR') param from dual;
PARAM
20-AUG-1999
SQL> Not lets check out the months. AUG seems pretty clear. Should be August the 8th month of the year.
Well not all peaple speak english...
SQL> alter session set nls_date_format = 'DD-MON-YYYY';
Session altered.
SQL> select TO_DATE ('20-AUG-99', 'DD-MON-RRRR') param from dual;
select TO_DATE ('20-AUG-99', 'DD-MON-RRRR') param from dual
ERROR at line 1:
ORA-01843: not a valid month
SQL>
/* Ok, lets check out how the moth is called in spain. */
SQL>  alter session set nls_date_format = 'DD Month  YYYY';
Session altered.
SQL> select TO_DATE ('20-08-99', 'DD-MM-RRRR') param from dual;
PARAM
20 Agosto      1999
SQL>
/* another way to make the original AUG working with spanish language settings would be to to use the third parameter of the to_date function */
SQL> select TO_DATE ('20-AUG-99', 'DD-MON-RRRR', 'nls_date_language=AMERICAN') from dual;
TO_DATE('20
20-AGO-1999
SQL> So your conversion of a string to date depends on several factors. You might not have ful control over all of them. There be as specific as it is possible in your environment. Try to avoid NLS-dependent logic like using names for a month. Use numbers instead.