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Rails 6.1 simplifies how to check whether an association exists by adding a new associated
method.
Let's see an example of it.
1class Account < ApplicationRecord
2 has_many :users, -> { joins(:contact).where.not(contact_id: nil) }
3end
This will return all users with contacts. If we rephrase that sentence then we can say that "this will return all users who are associated with contacts".
Let's see how we can do the same with the new associated
method.
1class Account < ApplicationRecord
2 has_many :users, -> { where.associated(:contact) }
3end
Now we can see that the usage of associated
decreases some of the syntactic noise we saw in the first example. This method is essentially a syntactic sugar over the inner_joins(:contact)
.
Check out the pull request for more details.