Rails ActiveRecord：从多个具有相同列名的表中抽签 [英] Rails ActiveRecord: Pluck from multiple tables with same column name

问题描述

我有一个简单的用例：

用户有很多推文
推文属于用户

User has many Tweets Tweet belongs to User

并且我试图选择两个表中都存在的列名。例如：

And i'm trying to pluck a column name that exists on both tables. For example:

@tweets = Tweet.includes(:user).all.pluck(:created_at)

每个表都有一个created_at列，但是上面的结果返回了tweet的created_at。我还如何选择用户的created_at？

Each table has a created_at column, but the result from above returns the created_at for the tweet. How can I also pluck the user's created_at?

我的解决方法是利用联接和选择进行操作：

My workaround is below utilizing joins and selects:

@tweets = Tweet.joins(:user).select("users.created_at AS created_date").all

那么如何通过使用pluck做到这一点？

So how can I do this by using pluck?

推荐答案

您可以执行以下操作

@tweets = Tweet.includes(:user).all.pluck(:created_at, "users.created_at")

而且 .all 在这里不是必需的，因为加入/包含获取所有 记录/相关记录 。因此，最终查询如下所示：

And also .all is not necessary here as joins/includes fetch all records/associated records. So the final query would be like below

@tweets = Tweet.includes(:user).pluck(:created_at, "users.created_at")

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