mysql - 如何在 MySQL 中做一个 foreach 等价物？

Question

这是一个 MySql 查询，用于打印构建的最后一个结果：

select * from buildresults where status in ('success','failed') 
and projectId=4 order by id desc limit 1

如何为一组 projectId 运行 for_each 等效查询？对于每个项目，我需要确定最后一次构建是成功还是失败。我不想考虑具有运行状态的构建。

我有另一个查询返回一组 projectId。

Answer 1

您想要的是将每个结果限制为 projectId 的最后一个。

select * from buildresults
where status in ('success','failed')
and id = 
(
  select max(id) from buildresults as b2
  where b2.status in ('success','failed') and
  b2.projectId = buildresults.projectId
)

Answer 2

你可以做这样的事情

    select * from buildresults 
where status in ('success','failed') 
    and projectId IN 
  (SELECT projectId from other_table where other condition)
  order by id desc

如果你想要最后的成功和失败，你可以试试这个

SELECT MAX(id),status FROM buildresults
WHERE status IN ('success','failed')
GROUP BY status

Answer 3

select * from buildresults where status in ('success','failed') 
group by project_id order by id desc

然后，您可以循环遍历所有结果，每行 1 个。