Question

one Article has many Comments, and i want to fetch all Articles that have Comments match a condition.

Article.find(:joins => :comments ...) 

fetch the duplicate records
and

Article.find(:include => :comments ...) 

will also fetch the Comment data,I just want to fetch the uniq Article data

Answer 1

You can try using

Article.select("DISTINCT articles.*").joins(:comments).where(...)

or with syntax you’re using

Article.find(:all, :joins => :comments, :select => 'DISTINCT articles.*' ...)