CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-3activerecord
George Armhold
George Armhold

Reputation: 31074

"where" queries using HQL-like syntax?

I'm a fan of Hibernate's HQL syntax, that lets me form queries that traverse model relationships, like:

from Book book where book.publisher.lastName = 'jones'
from Book book where book.chapters.length = 2

Is there an ActiveRecord syntax for traversing models like this?

Upvotes: 2

Views: 226

Answers (1)

MrTheWalrus
MrTheWalrus

Reputation: 9700

I think the closest you're going with to get with ARel is:

Book.joins(:publisher).where('publishers.lastName = ?', 'Jones')

or

Book.where(:publisher_id => Publisher.where(:last_name => 'Jones'))

(which is probably less efficient, as it will being hitting the database twice instead of once)

and

Book.joins(:chapters).group('books.id').having('count(chapters) = ?', 2)

Which I admit is a bit less readable.

There are some gems, Squeel is the one that comes to mind, which let you change up your query syntax in various ways - it's possible one of them will feel closer to what you want to use.

Upvotes: 1

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