Oracle統計某一年中的1-12個月的數據總和（非常實用）

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 人口數量爲0.類似效果如圖

創建表

 

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

 

插入數據

 

 

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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，只查詢到了數據中有的月，如果沒有就什麼也沒有顯示，和明顯不符合1-12個月的12條數據統計

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1	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條數據，而且是統計的結果的12條數據，從這裏入手編寫如下Sql語句，顯示12個列的統計數據，先查詢出一年的數據，然後再連接另外一條數據拼接

 

 

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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

 

 

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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數據對比使用left join查詢

 

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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) )) A left 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

實現與效果圖一樣的數據，可以將sql中的nums01...nums12改爲1月...12月

 

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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) )) A left 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

 

轉載自：https://www.2cto.com/database/201501/373557.html