sql percentile函數(shù) SQL中位數(shù)函數(shù)實例?
SQL中位數(shù)函數(shù)實例?SQL語句:代碼如下:(SELECT a1.Name,a1.Sales,COUNT(a2.sales) Sales_RankFROM Total_Sales a1,Total_S
SQL中位數(shù)函數(shù)實例?
SQL語句:
代碼如下:
(
SELECT a1.Name,a1.Sales,COUNT(a2.sales) Sales_Rank
FROM Total_Sales a1,Total_Sales a2
WHERE a1.Sales < a2.Sales or (a1.Sales=a2.Sales and a1.Name = a2.Name)
GROUP BY a1.Name,a1.Sales
ORDER BY a1.Sales DESC,a1.Name DESC
) as tab WHERE tab.sales_rank=(select (count(*) 1) div 2 from total_sales)
可以查找到中間的項,count(*) 1,這個1必須要添加,總項數(shù)假如為奇數(shù)7,則count(*) 1 / 2 = 4,假如是6則為3,都是滿足的,如果不 1的話,對奇數(shù)項則不滿足,如7,count(*) /2 = 3,而我們要查找的則是位于4的位置