追加模式这个SQL

Question

我有这样的SQL的MS SQL Server 2008中：

WITH CTE AS (
SELECT e_id, 
    scale, 
    ROW_NUMBER() OVER(PARTITION BY e_id ORDER BY scale ASC) AS rn, 
    COUNT(scale) OVER(PARTITION BY e_id) AS cn 
FROM waypoint.dbo.ScoreMaster 
WHERE scale IS NOT NULL 
) 
SELECT e_id, 

cast(AVG (cast(scale as decimal(5,2))) as decimal(5,3)) as [AVG], 

cast (STDEV(cast(scale as decimal(5,1))) as decimal(5,3)) as [STDDEV], 
AVG(CASE WHEN 2 * rn - cn BETWEEN 0 AND 2 THEN 
    scale END) AS FinancialMedian, 

MAX(CASE WHEN 2 * rn - cn BETWEEN 0 AND 2 THEN 
    scale END) AS StatisticalMedian 
from CTE 
GROUP BY e_id 

，我想补充的模式。 我一直在尝试不同的想法，但没有任何工程尚未...

Answer 1

WITH s (e_id, scale) AS 
     (
     SELECT 1, 0.0 
     UNION ALL 
     SELECT 1, 0.1 
     UNION ALL 
     SELECT 1, 0.1 
     UNION ALL 
     SELECT 1, 0.2 
     UNION ALL 
     SELECT 1, 0.2 
     UNION ALL 
     SELECT 1, 0.3 
     ), 
     cte AS 
     (
     SELECT e_id, 
       scale, 
       ROW_NUMBER() OVER (PARTITION BY e_id ORDER BY scale ASC) AS rn, 
       COUNT(scale) OVER (PARTITION BY e_id) AS cn, 
       COUNT(*) OVER (PARTITION BY e_id, scale) AS sn 
     FROM s 
     WHERE scale IS NOT NULL 
     ) 
SELECT e_id, 
     AVG(scale), 
     (
     SELECT AVG(scale) 
     FROM cte ci 
     WHERE ci.e_id = co.e_id 
       AND ci.sn = MAX(co.sn) 
     ) AS mode 
FROM cte co 
GROUP BY 
     e_id 

这将选择所有模态尺度的平均值。将AVG替换为TOP 1 ... ORDER BY以获得单一比例。

注意，我们怎么能WHERE条款:)

Answer 2

看看以下内容：

http://blogs.lessthandot.com/index.php/DataMgmt/DataDesign/calculating-mean-median-and-mode-with-sq

Answer 3

试试这个：

; WITH Mean AS (
SELECT AVG(scale)/1.0 AS MeanVal 
    FROM waypoint.dbo.ScoreMaster 
WHERE scale IS NOT NULL 
), Median AS (
SELECT ((SELECT TOP 1 scale 
      FROM (SELECT TOP 50 PERCENT scale FROM waypoint.dbo.ScoreMaster WHERE scale IS NOT NULL ORDER BY scale) AS A 
      ORDER BY scale DESC) 
     + (SELECT TOP 1 scale 
      FROM (SELECT TOP 50 PERCENT scale FROM waypoint.dbo.ScoreMaster WHERE scale IS NOT NULL ORDER BY scale DESC) AS A 
      ORDER BY scale ASC))/2.0 AS MedianVal 
), Mode AS (
SELECT scale AS ModeVal 
    FROM waypoint.dbo.ScoreMaster 
WHERE scale IS NOT NULL 
GROUP BY scale 
HAVING COUNT(scale) = (SELECT TOP 1 COUNT(scale) 
          FROM waypoint.dbo.ScoreMaster 
         WHERE scale IS NOT NULL 
         GROUP BY scale 
         ORDER BY COUNT(scale) DESC) 
) 
SELECT MeanVal 
    , MedianVal 
    , ModeVal 
    FROM Mean 
    , Median 
    , Mode 

我知道它的丑陋，但诀窍是交叉加入所有可能的值由给出模式值为平均值和中值。

Answer 4

或者这样：

; WITH Mean AS (
SELECT AVG(scale)/1.0 AS MeanVal 
    FROM waypoint.dbo.ScoreMaster 
WHERE scale IS NOT NULL 
), Median AS (
SELECT ((SELECT TOP 1 scale 
      FROM (SELECT TOP 50 PERCENT scale FROM waypoint.dbo.ScoreMaster WHERE scale IS NOT NULL ORDER BY scale) AS A 
      ORDER BY scale DESC) 
     + (SELECT TOP 1 scale 
      FROM (SELECT TOP 50 PERCENT scale FROM waypoint.dbo.ScoreMaster WHERE scale IS NOT NULL ORDER BY scale DESC) AS A 
      ORDER BY scale ASC))/2.0 AS MedianVal 
), Mode AS (
SELECT AVG(scale) AS ModeVal 
    FROM waypoint.dbo.ScoreMaster 
WHERE scale IS NOT NULL 
HAVING COUNT(scale) = (SELECT TOP 1 COUNT(scale) 
          FROM waypoint.dbo.ScoreMaster 
         WHERE scale IS NOT NULL 
         GROUP BY scale 
         ORDER BY COUNT(scale) DESC) 
) 
SELECT MeanVal 
    , MedianVal 
    , ModeVal 
    FROM Mean 
    , Median 
    , Mode 

如果你想模式是具有最高计数秤之间的AVG。