Doctrine2在Group By之前订购 [英] Doctrine2 Order By before Group By

问题描述

通常，在SQL中，您将执行一个子选择解决方案，以便在GROUP BY减少之前订购结果数据集。选择：

  SELECT * FROM（
 SELECT * FROM a_table order by a_table.timestamp desc 
）as table_tmp 
 group by userId 
  

但是，我在DQL中难以实现。
任何人都可以指向正确的方向吗？

我的查询比这更复杂，我假设我通过'table_tmp'加入其他表，并在外部SELECT。

感谢。

解决方案

恐怕DQL不能处理这样一个复杂的查询。但是Doctrine允许您编写一个自定义SQL查询并将其结果映射到对象中。

详细了解有关 Doctrine的文档页面。

I am having issues implementing a sub-select solution for ORDERING a resulting dataset before the GROUP BY reduces it.

Normally, in SQL you would do a sub-select:

SELECT * FROM (
    SELECT * FROM a_table order by a_table.timestamp desc
) as table_tmp
group by userId

However, I am having difficulty implementing this in DQL. Can anyone point me in the right direction please?

My query is more complex than this and I assume I JOIN other tables through 'table_tmp' and in the outer SELECT.

Thanks.

解决方案

I'm afraid DQL isn't able to handle such a complex query. However Doctrine allows you to write a custom SQL query and map its results into objects.

Read more about native queries on Doctrine's documentation pages.

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