簡單統計sql

select A.YY,
       sum(decode(A.mm, '01', A.NUM, 0)) as 一月,
       sum(decode(A.mm, '02', A.NUM, 0)) as 二月,
       sum(decode(A.mm, '03', A.NUM, 0)) as 三月,
       sum(decode(A.mm, '04', A.NUM, 0)) as 四月,
       sum(decode(A.mm, '05', A.NUM, 0)) as 五月,
       sum(decode(A.mm, '06', A.NUM, 0)) as 六月,
       sum(decode(A.mm, '07', A.NUM, 0)) as 七月,
       sum(decode(A.mm, '08', A.NUM, 0)) as 八月,
       sum(decode(A.mm, '09', A.NUM, 0)) as 九月,
       sum(decode(A.mm, '10', A.NUM, 0)) as 十月,
       sum(decode(A.mm, '11', A.NUM, 0)) as 十一月,
       sum(decode(A.mm, '12', A.NUM, 0)) as 十二月

  from (select count(1) num,
               substr(to_char(m.optdate, 'yyyyMM'), 0, 4) yy,
               substr(to_char(m.optdate, 'yyyyMM'), 5, 2) mm
          FROM czrzb M
         group by to_char(m.optdate, 'yyyyMM')) A
 group by A.YY
 order by A.YY

如圖：