Allow :select option with join-based include

+1

This is very handy: something I've needed quite a few times.

+1

Definitely needed. The current model precludes the access of join model data while eager loading - definitely not an optimal situation.

To illustrate the problem:

Schema

tag => id, name tagging => id, tag_id, taggable_id, taggable_type, context

has_many :through definition

has_many :people, :class_name => "Tag", :through => :people_taggings, :source => :tag, :select => "tags.*, taggings.context"

No eager loading, success

n = Node.first => #<Nodes::Book id: 1, ...> n.people.last.context => "author"

Eager loading, fails when getting join model data

n = Node.first :include => [:people] => #<Nodes::Book id: 1, ...> n.people.last.context NoMethodError: undefined method context' for #<Tag id: 16953, name: "Some Author">

the extra :select columns are being added after the join columns, we're using :select to specify SQL_CALC_FOUND_ROWS, which needs to be the first clause in the select, could the :select columns be preprended rather than appended to the list?

+1 This results in rails not understanding that my join tables are included thus querying the DB for each value from the joined tables.

I'd actually like to see this in core - I just had a valid use case for it when I wanted to concatenate strings found in sepearate tables.

While the plugin is useful, I don't want to create unnecessary dependencies when I believe this should actually be a feature within core.

You should be able to derive columns in a finder ubiquitously.

+1

Would also like to see this in code

+1

s/code/core

yeah for not being able to edit comments :(