当前日期的周日日期怎么取得

当前日期的周日日期如何取得

update DIM_TIME f   set f.firstday_of_week = case                              when f.full_date < round(f.full_date, 'day') then                               to_char(round(f.full_date, 'day') - 7,                                       'yyyy-mm-dd')                              else                               to_char(round(f.full_date, 'day'),                                       'yyyy-mm-dd')                            end   where f.year<2012

select f.firstday_of_week,       case         when f.full_date < round(f.full_date, 'day') then          to_char(round(f.full_date, 'day') - 7, 'yyyy-mm-dd')         else          to_char(round(f.full_date, 'day'), 'yyyy-mm-dd')       end  from dim_time f where f.year<2012;