如何簡化多選查詢以加快執行速度？

SQLFiddle here：http://sqlfiddle.com/#!9/b88d1a/1/0 ---注意由於大約8000個字符的限制，並且沒有查詢無法運行的最小數據量，我無法在SQLFiddle中加載足夠的插入。因此，SQL插入位於此pastebin文件中：https://pastebin.com/MfhJ0Svc - 我無法將320插入行粘貼到Fiddle中，或者抱歉。如何簡化多選查詢以加快執行速度？

我有一個表格，然後是一個名爲Review的視圖，它包含一個只有唯一用戶名的列。該表稱爲RebasedQuestions，目前包含大約40000條記錄。

該表用於計算人們對人們進行的一系列評論。

查詢需要產生一個最終表格，它以百分比的形式給出了主管，自己，同行和下屬的值，然後是6以外的值（評論問題選項的範圍從1到6）。而每評審類型的權重分別是：

Supervisor: 30% 
Own: 0% 
Peer: 40% 
Subordinate: 30%

這裏是DDL的觀點：

CREATE VIEW Reviewed AS 
    SELECT DISTINCT `t1`.`Reviewed` AS `Reviewed` 
    FROM `edsdb`.`RebasedQuestions` `t1` 
    ORDER BY `t1`.`Reviewed`;

而且DDL主表：

create table RebasedQuestions 
(
    Reviewed varchar(50) null, 
    ReviewType varchar(20) null, 
    BU int null, 
    RebasedValue double null 
) 
;

這是我的查詢，但我認爲它還遠沒有優化，所以請賜教如何加快這一點起來，尤其是在主表與每一個新的審查，提交時間爲20線增長：

select DISTINCT t1.Reviewed, t2.BU, 
    (SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Supervisor') AS Supervisor, 
    (((SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Supervisor')/100) * 6) as Sup6, 
    (SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Own') AS Own, 
    (((SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Own')/100) * 6) as Own6, 
    (SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Peer') AS Peer, 
    (((SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Peer')/100) * 6) as Peer6, 
    (SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Subordinate') AS Subordinate, 
    (((SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Subordinate')/100) * 6) as Sub6, 
    (ifnull((((SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Supervisor')/100) * 6),6) * 0.3 + 
    ifnull((((SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Peer')/100) * 6),6) * 0.4 + 
    ifnull((((SELECT ((sum(t2.RebasedValue)/(count(t2.RebasedValue)/20))) from RebasedQuestions t2 WHERE t2.Reviewed = t1.Reviewed and t2.ReviewType = 'Subordinate')/100) * 6),6) * 0.3) as Totaled 
from Reviewed t1 JOIN RebasedQuestions t2 on t1.Reviewed = t2.Reviewed

我甚至不能粘貼在這裏插入體內。

他們可以在這個引擎收錄鏈接上找到：https://pastebin.com/MfhJ0Svc

來源

2017-09-15 georgelappies

您還可以提供一些樣本和所需的數據 –

請提供您期望的樣本輸入和輸出。即使沒有任何調整，如果沒有比您寫的更有效的查詢，我會感到震驚。 –

作爲@MKhalidJunaid說，請它會很好，如果使用這個工具 sqlfiddle.com – ARr0w

下面是你應該能夠適應你的需要的建議。

SELECT 
innerQuery.Reviewed, 
innerQuery.BU, 
(CASE WHEN (innerQuery.supcount=0) then null else 
innerQuery.suptot/innerQuery.supcount end) as sup, 
(CASE WHEN (innerQuery.supcount=0) then null else 
(6*innerQuery.suptot)/(100*innerQuery.supcount) end) as sup6 
... 
(CASE WHEN (innerQuery.supcount=0) then 1.8 else sup6*0.3 end)+ ... as totaled 
from 
(SELECT 
Reviewed, 
BU, 
(SUM(ReviewType='Supervisor') then RebasedValue else 0 end) as 
suptot 
(COUNT(ReviewType='Supervisor') then RebasedValue else 0 end) as 
supcount, 
... 
FROM RebasedQuestions GROUP BY Reviewed, BU) innerQuery

來源

2017-09-15 08:18:33 Taemyr

在手機atm上，謝謝你的回答。將盡快測試並回復;） – georgelappies

如何簡化多選查詢以加快執行速度？

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