Question

Is there a way to get the actual columns name with ActiveRecord?

When I call find_by_sql or select_all with a join, if there are columns with the same name, the first one get overridden:

select locations.*, s3_images.* from locations left join s3_images on s3_images.imageable_id = locations.id and s3_images.imageable_type = 'Location' limit 1

In the example above, I get the following:

#<Location id: 22, name: ... 
>

Where id is that of the last s3_image. select_rows is the only thing that worked as expected:

Model.connection.select_rows("SELECT id,name FROM users") => [["1","amy"],["2","bob"],["3","cam"]]

I need to get the field names for the rows above.
This post gets close to what I want but looks outdated (fetch_fields doesn’t seem to exist anymore How do you get the rows and the columns in the result of a query with ActiveRecord? )

The ActiveRecord join method creates multiple objects. I’m trying to achieve the same result “includes” would return but with a left join.

I am attempting to return a whole lot of results (and sometimes whole tables) this is why includes does not suit my needs.

Answer 1

Active Record provides a #column_names method that returns an array of column names.

Usage example: User.column_names