如何插入新行的百分比

Question

有這個疑問：

select t.cod_provincia as prov, COUNT(t.cod_provincia) as conto 
from clienti t 
where t.data_ins between to_date(&da_data,'ddmmrr') and to_date(&a_data,'ddmmrr') 
and t.cod_iso='ITA' 
group by t.cod_provincia 

返回

現在我想要一個新的關口以百分比來查看CONTO值的每一行。我可以做嗎？ 對於每一行我想要的值[CONTO*100]/SUM(CONTO)

Answer 1

select pov, conto*100/sum(conto) over() 
    from (
     select t.cod_provincia as prov, COUNT(t.cod_provincia) as conto 
     from clienti t 
     where t.data_ins between to_date(&da_data,'ddmmrr') and to_date(&a_data,'ddmmrr') 
      and t.cod_iso='ITA' 
     group by t.cod_provincia 
     ) 

Answer 2

SELECT t.cod_provincia  AS prov, 
     Count(t.cod_provincia) AS conto, 
     (Count(t.cod_provincia) * 100)/Sum(cod_provincia) 
FROM clienti t 
WHERE t.data_ins between to_date(&da_data,'ddmmrr') and to_date(&a_data,'ddmmrr') 
and t.cod_iso = 'ITA' 
GROUP BY t.cod_provincia 

Answer 3

Oracle有一個內置的，可以用來作爲一種替代生鏽的解決方案解析函數RATIO_TO_REPORT：

select t.cod_provincia as prov, 
     count(t.cod_provincia) as conto, 
     100*RATIO_TO_REPORT(count(t.cod_provincia)) OVER() as percentage 
from clienti t 
where t.data_ins between to_date(&da_data,'ddmmrr') and to_date(&a_data,'ddmmrr') 
and t.cod_iso='ITA' 
group by t.cod_provincia 

它給出了同樣的結果，但避免重複一個表達式作爲分子和分母內的總和。而且您不必擔心可能會被零錯誤分割。