Thursday, June 11, 2015
I would not recommend using a default scope on an ActiveRecord model for sorting.
Start your Rails console and try Model.find(1). This will result into: SELECT models.* FROM models WHERE models.id=1 ORDER BY id DESC LIMIT 1
This ORDER BY will be included in every unneccessary query. The above query will be slower in MySQL than without the ORDER BY clause. Try it yourself!
Create a normal scope and include it with every query where you expect more than 1 record as a result.
In case you consider a mixin try http://api.rubyonrails.org/classes/ActiveSupport/Concern.html
-- Start your Rails console and try Model.find(1). This will result into: SELECT models.* FROM models WHERE models.id=1 ORDER BY id DESC LIMIT 1
This ORDER BY will be included in every unneccessary query. The above query will be slower in MySQL than without the ORDER BY clause. Try it yourself!
Create a normal scope and include it with every query where you expect more than 1 record as a result.
In case you consider a mixin try http://api.rubyonrails.org/classes/ActiveSupport/Concern.html
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