查询当前时间所在月份的日历
select sum(d1) 星期日,
sum(d2) 星期一,
sum(d3) 星期二,
sum(d4) 星期三,
sum(d5) 星期四,
sum(d6) 星期五,
sum(d7) 星期六
from (select decode(d, 1, l) d1,
decode(d, 2, l) d2,
decode(d, 3, l) d3,
decode(d, 4, l) d4,
decode(d, 5, l) d5,
decode(d, 6, l) d6,
decode(d, 7, l) d7,
case
when d >= fd then
row_number() over(partition by d order by l) - 1
else
row_number() over(partition by d order by l)
end ro
from (select level l,--日期
to_char(add_months(last_day(sysdate), -1) + level, 'd') d,--星期几
to_char(add_months(last_day(sysdate), -1) + 1, 'd') fd --第一天星期几
from dual
connect by level <= to_char(last_day(sysdate), 'dd')))
group by ro
order by nvl(sum(d1) ,0)
