如何简化多选查询以加快执行速度？

SQLFiddle here：http://sqlfiddle.com/#!9/b88d1a/1/0 ---注意由于大约8000个字符的限制，并且没有查询无法运行的最小数据量，我无法在SQLFiddle中加载足够的插入。因此，SQL插入位于此pastebin文件中：https://pastebin.com/MfhJ0Svc - 我无法将320插入行粘贴到Fiddle中，或者抱歉。如何简化多选查询以加快执行速度？

我有一个表格，然后是一个名为Review的视图，它包含一个只有唯一用户名的列。该表称为RebasedQuestions，目前包含大约40000条记录。

该表用于计算人们对人们进行的一系列评论。

查询需要产生一个最终表格，它以百分比的形式给出了主管，自己，同行和下属的值，然后是6以外的值（评论问题选项的范围从1到6）。而每评审类型的权重分别是：

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

这里是DDL的观点：

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 
) 
;

这是我的查询，但我认为它还远没有优化，所以请赐教如何加快这一点起来，尤其是在主表与每一个新的审查，提交时间为20线增长：

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

我甚至不能粘贴在这里插入体内。

他们可以在这个引擎收录链接上找到：https://pastebin.com/MfhJ0Svc

来源

2017-09-15 georgelappies

您还可以提供一些样本和所需的数据 –

请提供您期望的样本输入和输出。即使没有任何调整，如果没有比您写的更有效的查询，我会感到震惊。 –

作为@MKhalidJunaid说，请它会很好，如果使用这个工具 sqlfiddle.com – ARr0w

下面是你应该能够适应你的需要的建议。

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

来源

2017-09-15 08:18:33 Taemyr

在手机atm上，谢谢你的回答。将尽快测试并回复;） – georgelappies

如何简化多选查询以加快执行速度？

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