re-write active record query to PostgreSQL

I want to rewrite the active record query to Actual PostgreSQL query

Camera.joins("left JOIN users on cameras.owner_id = users.id")
                    .joins("left JOIN vendor_models vm on cameras.model_id = vm.id")
                    .joins("left JOIN vendors v on vm.vendor_id = v.id")
                    .where(condition).order(sorting(col_for_order, order_for))

as you can see how these tables are related in the above joins.

also conditions could be

"lower(cameras.exid) like lower('%#{params[:fquery]}%') OR lower(cameras.name) like lower('%#{params[:fquery]}%') OR
      lower(vm.name) like lower('%#{params[:fquery]}%') OR lower(v.name) like lower('%#{params[:fquery]}%')
      OR lower(users.firstname || ' ' || users.lastname) like lower('%#{params[:fquery]}%') OR
      lower(cameras.config->>'external_host') like lower('%#{params[:fquery]}%')

Reason of writing this query, I have another table camera_shares which is related to cameras table with camera_id, I also want to get the count of camera_shares against a camera_id, How could that be possible to geth the similar results in PostgreSQL