Week of the year number appears out of sync with the day of week the week #

Question

Using the querry below on on a table where the pdate value is a sequential list of dates on an Oracle 11 database the results show the week of the year number changes on the day of the week number 7 not the day of the week number 1. Is there a patch to fix this?
select
pdate,
to_char(pdate,'D') dow,
to_char(pdate,'Day') Day_name,
to_char(pdate,'WW') week_of_the_Year
from daily_period_tab
where pdate >= '07-jan-11'
and pdate <= '09-jan-11'
07-JAN-11     6     Friday      01
08-JAN-11     7     Saturday      02
09-JAN-11     1     Sunday      02

Answer 1

Hi,
Independent of you NLS settings, you can do this:
SELECT     TRUNC ( dt + 1
           , 'IW'
           ) - 1     AS sunday
FROM     table_x;The output in the sunday column will be the Sunday on or before dt. The "magic number" 1 indicates that your week starts 1 day before the ISO week, which starts on Monday.
Or if you want to use your NLS settings:
ALTER SESSION     SET NLS_TERRITORY= 'AMERICA';
SELECT     TRUNC ( dt
           , 'DY'
           )          AS sunday
FROM    table_x; 
I hope this answers your question.
If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) for all tables, and also post the results you want from that data.
Explain, using specific examples, how you get those results from that data.
Always say which version of Oracle you're using.