Question

假设我有以下对象：

Site: 

idSite,
name
and other static data. 

Test:

idTest
idSite
name
and other static data.

Site Version:

idSiteVersion,
idSite
name of version


Test Result:

ןdTestResult
idSiteVersion, 
idTest,
timeEnded

对于每个站点，都有一个为他注册的测试列表。

现在我想知道每个site version最新的testresults，按idTest分组。以及未经测试的人，以null为值。（b）

我为此建立了一个数据库。

但是我很难得到我列出的查询（b），这需要相当长的时间。

我正在考虑改造它。任何建议都会有所帮助

新的将包含一个表LATEST，它将充当缓存，
所以我将在insert上使用触发器来更新右行，
并将从中进行选择。

是吗？
我应该改造吗？

查询：

select `tr1`.`id` AS `id`,
`dsv`.`idSite_id` AS `idSite`,
`tr1`.`idSiteVersion_id` AS `idSiteVersion`,
`tr1`.`idTest_id` AS `idTest`,
`tr1`.`result` AS `result`,
`tr1`.`timeStarted` AS `timeStarted`,
 from 
`dash`.`testresult` `tr1` 
join `dash`.`siteversion` `dsv` on `dsv`.`id` = `tr1`.`idSiteVersion_id`
join `dash`.`test` `dtest` on `dtest`.`id` = `tr1`.`idTest_id` 
where `dtest`.`ignored` = 0 and `tr1`.`timeEnd` = 
( select max(`tr2`.`timeEnd`) from `dash`.`testresult` `tr2` 
    where 
       ((`tr2`.`idTest_id` = `tr1`.`idTest_id`) and 
       (`tr2`.`idSiteVersion_id` = `tr1`.`idSiteVersion_id`) and 
       (`tr2`.`timeEnd` is not null)))

Answer 1

试试这样：

SELECT
  tr1.id AS id,
  dsv.idSite_id AS idSite,
  tr1.idSiteVersion_id AS idSiteVersion,
  tr1.idTest_id AS idTest,
  tr1.result AS result,
  tr1.timeStarted AS timeStarted,
FROM 
  dash.testresult AS tr1 
  NATURAL JOIN (
    SELECT idTest_id, idSiteVersion_id, MAX(timeEnd) AS timeEnd
    FROM dash.testresult
    WHERE timeEnd IS NOT NULL
    GROUP BY idTest_id, idSiteVersion_id
  ) AS tr2
  JOIN dash.siteversion AS dsv
    ON dsv.id = tr1.idSiteVersion_id
  JOIN dash.test AS dtest
    ON dtest.id = tr1.idTest_id AND dtest.ignored = 0

此外，如果您还没有索引，那么您肯定想在dash.testresult (idTest_id, idSiteVersion_id, timeEnd)上创建一个索引。

设计DB时需要知道最新的东西

1 个答案: