Oracle 統計某一年中的1-12個月的資料總和（非常實用），oracle1-12

Oracle 統計某一年中的1-12個月的資料總和（非常實用），oracle1-12
實戰案例

        查詢2015年1月到12個月的所有實有人口數量和往年2014年1月到12個月的實有人口數量，沒有的月份顯示 人口數量為0.類似效果

建立表

create table PERSONSITUATION(  id    NUMBER not null,  rdate DATE,  nums  NUMBER)

插入資料

insert into PERSONSITUATION (id, rdate, nums) values (1, to_date('26-01-2015', 'dd-mm-yyyy'), 131);insert into PERSONSITUATION (id, rdate, nums) values (2, to_date('27-01-2013', 'dd-mm-yyyy'), 232);insert into PERSONSITUATION (id, rdate, nums) values (3, to_date('18-10-2013', 'dd-mm-yyyy'), 222);insert into PERSONSITUATION (id, rdate, nums) values (4, to_date('20-01-2015', 'dd-mm-yyyy'), 232);insert into PERSONSITUATION (id, rdate, nums) values (5, to_date('28-01-2015', 'dd-mm-yyyy'), 422);insert into PERSONSITUATION (id, rdate, nums) values (6, to_date('26-02-2015', 'dd-mm-yyyy'), 232);insert into PERSONSITUATION (id, rdate, nums) values (7, to_date('29-01-2014', 'dd-mm-yyyy'), 225);insert into PERSONSITUATION (id, rdate, nums) values (8, to_date('31-01-2015', 'dd-mm-yyyy'), 111);insert into PERSONSITUATION (id, rdate, nums) values (9, to_date('25-01-2013', 'dd-mm-yyyy'), 211);insert into PERSONSITUATION (id, rdate, nums) values (10, to_date('25-01-2013', 'dd-mm-yyyy'), 251);insert into PERSONSITUATION (id, rdate, nums) values (11, to_date('25-01-2013', 'dd-mm-yyyy'), 262);insert into PERSONSITUATION (id, rdate, nums) values (12, to_date('25-08-2015', 'dd-mm-yyyy'), 233);insert into PERSONSITUATION (id, rdate, nums) values (13, to_date('25-01-2013', 'dd-mm-yyyy'), 211);insert into PERSONSITUATION (id, rdate, nums) values (14, to_date('25-02-2014', 'dd-mm-yyyy'), 222);insert into PERSONSITUATION (id, rdate, nums) values (15, to_date('25-03-2012', 'dd-mm-yyyy'), 209);insert into PERSONSITUATION (id, rdate, nums) values (16, to_date('25-01-2012', 'dd-mm-yyyy'), 219);

常見的統計中如下Sql語句，只查詢到了資料中有的月，如果沒有就什麼也沒有顯示，和明顯不符合1-12個月的12條資料統計

select to_char(rdate,'yyyy-mm') rdate,sum(nums) nums from personsituation where to_char(rdate,'yyyy')='2015' group by to_char(rdate,'yyyy-mm') order by rdate

正確的分析是：必須是12條資料，而且是統計的結果的12條資料，從這裡入手編寫如下Sql語句，顯示12個列的統計資料，先查詢出一年的資料，然後再串連另外一條資料拼接

select sum(decode(to_char(rdate,'mm'),'01',nums,0)) nums01,sum(decode(to_char(rdate,'mm'),'02',nums,0)) nums02,       sum(decode(to_char(rdate,'mm'),'03',nums,0)) nums03,sum(decode(to_char(rdate,'mm'),'04',nums,0)) nums04,        sum(decode(to_char(rdate,'mm'),'05',nums,0)) nums05,sum(decode(to_char(rdate,'mm'),'06',nums,0)) nums06,       sum(decode(to_char(rdate,'mm'),'07',nums,0)) nums07,sum(decode(to_char(rdate,'mm'),'08',nums,0)) nums08,       sum(decode(to_char(rdate,'mm'),'09',nums,0)) nums09,sum(decode(to_char(rdate,'mm'),'10',nums,0)) nums10,       sum(decode(to_char(rdate,'mm'),'11',nums,0)) nums11,sum(decode(to_char(rdate,'mm'),'12',nums,0)) nums12           from personsituation            where to_char(rdate,'yyyy')='2015' 

而前端頁面顯示的結果有兩種可能性，一種是橫向展示，一種是縱向展示，可以使用下面的sql語句進行列轉行的轉換得到如下結果

select * from (  select sum(decode(to_char(rdate,'mm'),'01',nums,0)) nums01,sum(decode(to_char(rdate,'mm'),'02',nums,0)) nums02,     sum(decode(to_char(rdate,'mm'),'03',nums,0)) nums03,sum(decode(to_char(rdate,'mm'),'04',nums,0)) nums04,      sum(decode(to_char(rdate,'mm'),'05',nums,0)) nums05,sum(decode(to_char(rdate,'mm'),'06',nums,0)) nums06,     sum(decode(to_char(rdate,'mm'),'07',nums,0)) nums07,sum(decode(to_char(rdate,'mm'),'08',nums,0)) nums08,     sum(decode(to_char(rdate,'mm'),'09',nums,0)) nums09,sum(decode(to_char(rdate,'mm'),'10',nums,0)) nums10,     sum(decode(to_char(rdate,'mm'),'11',nums,0)) nums11,sum(decode(to_char(rdate,'mm'),'12',nums,0)) nums12         from personsituation          where to_char(rdate,'yyyy')='2015' )  unpivot (sum2015 for years in (nums01,nums02,nums03,nums04,nums05,nums06,nums07,nums08,nums09,nums10,nums11,nums12) )

最後一步就是和往年的資料對比使用left join查詢

select A.years,A.SUM2015,B.SUM2014 from       (select * from (    select sum(decode(to_char(rdate,'mm'),'01',nums,0)) nums01,sum(decode(to_char(rdate,'mm'),'02',nums,0)) nums02,       sum(decode(to_char(rdate,'mm'),'03',nums,0)) nums03,sum(decode(to_char(rdate,'mm'),'04',nums,0)) nums04,        sum(decode(to_char(rdate,'mm'),'05',nums,0)) nums05,sum(decode(to_char(rdate,'mm'),'06',nums,0)) nums06,       sum(decode(to_char(rdate,'mm'),'07',nums,0)) nums07,sum(decode(to_char(rdate,'mm'),'08',nums,0)) nums08,       sum(decode(to_char(rdate,'mm'),'09',nums,0)) nums09,sum(decode(to_char(rdate,'mm'),'10',nums,0)) nums10,       sum(decode(to_char(rdate,'mm'),'11',nums,0)) nums11,sum(decode(to_char(rdate,'mm'),'12',nums,0)) nums12           from personsituation            where to_char(rdate,'yyyy')='2015'   ) unpivot (sum2015 for years in (nums01,nums02,nums03,nums04,nums05,nums06,nums07,nums08,nums09,nums10,nums11,nums12) )) Aleft join  (select * from (    select sum(decode(to_char(rdate,'mm'),'01',nums,0)) nums01,sum(decode(to_char(rdate,'mm'),'02',nums,0)) nums02,       sum(decode(to_char(rdate,'mm'),'03',nums,0)) nums03,sum(decode(to_char(rdate,'mm'),'04',nums,0)) nums04,        sum(decode(to_char(rdate,'mm'),'05',nums,0)) nums05,sum(decode(to_char(rdate,'mm'),'06',nums,0)) nums06,       sum(decode(to_char(rdate,'mm'),'07',nums,0)) nums07,sum(decode(to_char(rdate,'mm'),'08',nums,0)) nums08,       sum(decode(to_char(rdate,'mm'),'09',nums,0)) nums09,sum(decode(to_char(rdate,'mm'),'10',nums,0)) nums10,       sum(decode(to_char(rdate,'mm'),'11',nums,0)) nums11,sum(decode(to_char(rdate,'mm'),'12',nums,0)) nums12           from personsituation            where to_char(rdate,'yyyy')='2014'   ) unpivot (sum2014 for years in (nums01,nums02,nums03,nums04,nums05,nums06,nums07,nums08,nums09,nums10,nums11,nums12) )) B on A.years = B.years

實現與一樣的資料，可以將sql中的nums01...nums12改為1月...12月

select A.years,A.SUM1,B.SUM2 from       (select * from (    select sum(decode(to_char(rdate,'mm'),'01',nums,0)) 一月,sum(decode(to_char(rdate,'mm'),'02',nums,0)) 二月,       sum(decode(to_char(rdate,'mm'),'03',nums,0)) 三月,sum(decode(to_char(rdate,'mm'),'04',nums,0)) 四月,        sum(decode(to_char(rdate,'mm'),'05',nums,0)) 五月,sum(decode(to_char(rdate,'mm'),'06',nums,0)) 六月,       sum(decode(to_char(rdate,'mm'),'07',nums,0)) 七月,sum(decode(to_char(rdate,'mm'),'08',nums,0)) 八月,       sum(decode(to_char(rdate,'mm'),'09',nums,0)) 九月,sum(decode(to_char(rdate,'mm'),'10',nums,0)) 十月,       sum(decode(to_char(rdate,'mm'),'11',nums,0)) 十一月,sum(decode(to_char(rdate,'mm'),'12',nums,0)) 十二月           from personsituation            where to_char(rdate,'yyyy')= '2015'  ) unpivot (sum1 for years in (一月,二月,三月,四月,五月,六月,七月,八月, 九月,十月,十一月,十二月) )) Aleft join  (select * from (    select sum(decode(to_char(rdate,'mm'),'01',nums,0)) 一月,sum(decode(to_char(rdate,'mm'),'02',nums,0)) 二月,       sum(decode(to_char(rdate,'mm'),'03',nums,0)) 三月,sum(decode(to_char(rdate,'mm'),'04',nums,0)) 四月,        sum(decode(to_char(rdate,'mm'),'05',nums,0)) 五月,sum(decode(to_char(rdate,'mm'),'06',nums,0)) 六月,       sum(decode(to_char(rdate,'mm'),'07',nums,0)) 七月,sum(decode(to_char(rdate,'mm'),'08',nums,0)) 八月,       sum(decode(to_char(rdate,'mm'),'09',nums,0)) 九月,sum(decode(to_char(rdate,'mm'),'10',nums,0)) 十月,       sum(decode(to_char(rdate,'mm'),'11',nums,0)) 十一月,sum(decode(to_char(rdate,'mm'),'12',nums,0)) 十二月           from personsituation            where to_char(rdate,'yyyy')= '2014'  ) unpivot (sum2 for years in (一月,二月,三月,四月,五月,六月,七月,八月, 九月,十月,十一月,十二月) )) B on A.years = B.years

行轉列，列轉行有不懂得地方可以參考文章：http://blog.csdn.net/xiaokui_wingfly/article/details/42419207  覺得不錯記得點贊瀏覽，謝謝