Selecting all columns with Inner Join in Active Record

问题

In the Ruby on Rails Guide I see examples using Joins. For example

Category.joins(:posts)

results in the query

SELECT categories.* FROM categories
  INNER JOIN posts ON posts.category_id = categories.id

This is all well and good, but how can I get returned both the categories AND posts columns using Active Record? Or am I totally missing something with SQL?

回答1:

You need to call #includes:

Category.includes(:posts)

来源：https://stackoverflow.com/questions/14947820/selecting-all-columns-with-inner-join-in-active-record