1st of the Quarter for yesterday.....

Question

Morning everyone,
I need to write a bit of code that will retrieve the first day of the quarter, based upon yesterday's date (ie 1st of the Q for yesterday would be 01/04/2007). I have managed to achieve this using the following code:
select
case to_char(sysdate-1, 'mm')
when '01' then '01/01/'||to_char(sysdate-1, 'yyyy')
when '02' then '01/01/'||to_char(sysdate-1, 'yyyy')
when '03' then '01/01/'||to_char(sysdate-1, 'yyyy')
when '04' then '01/04/'||to_char(sysdate-1, 'yyyy')
when '05' then '01/04/'||to_char(sysdate-1, 'yyyy')
when '06' then '01/04/'||to_char(sysdate-1, 'yyyy')
when '07' then '01/07/'||to_char(sysdate-1, 'yyyy')
when '08' then '01/07/'||to_char(sysdate-1, 'yyyy')
when '09' then '01/07/'||to_char(sysdate-1, 'yyyy')
when '10' then '01/10/'||to_char(sysdate-1, 'yyyy')
when '11' then '01/10/'||to_char(sysdate-1, 'yyyy')
when '12' then '01/10/'||to_char(sysdate-1, 'yyyy')
end as QTD
from dual;
However, I need to retrieve the result in 'date' format - the above is char. Could anyone kindly point me in the right direction?? (I have tried replacing the to_char's with to_dates, and enclosing the to_char in a to_date - but it either doesnt work, or the format is screwey).
Alternatively - would there be a simplier way to code this?? (I have only been writing SQL for a few months).
Any help would be greatly appreciated.
Kind regards,
P

Answer 1

sql>
select trunc(sysdate-1,'Q') dt
from dual;
DT
01-APR-07