How to get posts by tags?

Question

Ruby on Rails

I have 2 models connected via a third has_many :through
create_table "posts", force: :cascade do |t|
t.string "title"
t.text "body"
end
create_table "tags", force: :cascade do |t|
t.string "name"
end
create_table "tags_associations", force: :cascade do |t|
t.integer "post_id"
t.integer "tag_id"
end
How should a request to get all posts for a specific tag look like when receiving such a param. Parameters: {"tag"=>"3"}.

Answer 1

@posts = Post.posts_for_tag(params[:tag])
scope :posts_for_tag, -> (tag) do
includes(:tags_associations, :tags)
.joins(:tags)
.where("tags_associations.tag_id = ?", tag )
end
decided himself right or wrong, but it seems to work)