mysql – 一个非常大的SQL查询的问题

问题：

我正在创建一个Trac报告,显示我们库中每章开发周期中每个阶段的票数.门票代表单件作品,通常是个人例程.

例如,即将发布的版本(里程碑)的票数在第十章的同行评审阶段.

共有10个开发阶段和47个章节.

给定的MySQL查询适用于所有10个开发阶段,但只有一个章节并且长度为25行,因此所有章节的整个查询超过1200行.

Trac给出的错误是KeyError：’numrows’,查询变得很大.

当直接向MySQL输入查询时,给出的错误是打开文件时的资源不足(错误代码：24)(23)

题 ：

>重构 – 这可以做得更好’sql专家,有一些聪明的技巧/先进技巧吗？
>方法 – 我是否需要完全不同的方法？
>配置 – 可以将MySQL和/或Trac配置为接受非常大的查询

笔记：

表中的数据很小,查询在表观大小限制下执行时间不长.

查询从Trac系统传递到MySQL,这对可以执行的操作设置了一些限制,例如,只能从trac发送一个查询来生成报告.

可以在here.看到Trac报告的示例

查询中的％c％*只是我通过脚本生成查询时用于替换实际章节的唯一字符串.

SELECT '%c%' as Chapter,
(SELECT count(ticket.id) AS Matches FROM engine.ticket INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%' AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine' AND ticket.status IN ('new','assigned') ) AS 'New',
(SELECT count(ticket.id) AS Matches FROM engine.ticket INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%' AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine' AND ticket.status='document_interface' ) AS 'Document\
 Interface',
(SELECT count(ticket.id) AS Matches FROM engine.ticket INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%' AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine' AND ticket.status='interface_development' ) AS 'Inter\
face Development',
(SELECT count(ticket.id) AS Matches FROM engine.ticket INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%' AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine' AND ticket.status='interface_check' ) AS 'Interface C\
heck',
(SELECT count(ticket.id) AS Matches FROM engine.ticket INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%' AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine' AND ticket.status='document_routine' ) AS 'Document R\
outine',
(SELECT count(ticket.id) AS Matches FROM engine.ticket INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%' AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine' AND ticket.status='full_development' ) AS 'Full Devel\
opment',
(SELECT count(ticket.id) AS Matches FROM engine.ticket INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%' AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine' AND ticket.status='peer_review_1' ) AS 'Peer Review O\
ne',
(SELECT count(ticket.id) AS Matches FROM engine.ticket INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%'AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine' AND ticket.status='peer_review_2' ) AS 'Peer Review Tw\
o',
(SELECT count(ticket.id) AS Matches FROM engine.ticket INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%' AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine' AND ticket.status='qa' ) AS 'QA',
(SELECT count(ticket.id) AS Matches FROM engine.ticket INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%'AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine' AND ticket.status='closed' ) AS 'Closed',
count(id) AS Total,
ticket.id AS _id
FROM engine.ticket
INNER JOIN engine.ticket_custom ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' AND ticket_custom.value LIKE '%c%' AND type='New material' AND milestone='1.1.12' AND component NOT LIKE 'internal_engine'

解决方法:

不会完全改写它……但这是我的建议：

SELECT '%c%' as Chapter,
    SUM(CASE WHEN ticket.status IN ('new','assigned') THEN 1 ELSE 0 END) as `New`,
    ...
    SUM(CASE WHEN ticket.status='closed' THEN 1 ELSE 0 END) as 'Closed',
    count(id) AS Total,
    ticket.id AS _id
FROM engine.ticket
INNER JOIN engine.ticket_custom 
    ON ticket.id = ticket_custom.ticket
WHERE ticket_custom.name='chapter' 
    AND ticket_custom.value LIKE '%c%' 
    AND type='New material' 
    AND milestone='1.1.12' 
    AND component NOT LIKE 'internal_engine'
GROUP BY ticket.id
;

标签：trac,sql,mysql,refactoring
来源： https://codeday.me/bug/20190901/1785489.html