问题
I have a huge complex query like this:
@objects = Object.joins({ x: :y }).includes(
[:s, { x: { y: :z } }, { l: :m },:q, :w,
{ important_thing:
[:h, :v, :c,:l, :b, { :k [:u, :a] }]
}
]).where(conditions).order("x.foo, x.bar")
Then i want to show all Objects
and only Important_things
that were created at between two dates.
If i put this on there where
clause i dont get all Objects
, only Objects
that has Important_things
between informed dates.
A solution using raw sql was this:
select * from objects left join important_things on important_things.object_id = objets.id and important_things.created_at between 'x' and 'y'
Instead of:
select * from objects left join important_things on important_things.object_id = objets.id where important_things.created_at between 'x' and 'y'
I really need all those objects and i don't want to use a raw SQL, any workaround or a possibility to pass parameters to the ON
clause on an association?
回答1:
I do this,
class VendorsRatings < ActiveRecord::Base
def self.ratings(v_ids,sort = "DESC")
joins("RIGHT OUTER JOIN vendors_lists v
ON v.vendor_id = vendors_ratings.vendor_id").where(conditions)
end
end
回答2:
I did a ugly workaround:
class Parent < ActiveRecord::Base
cattr_accessor :dt_begin, dt_end
has_many :children, conditions: Proc.new { { created_at: (@@dt_begin..@@dt_end) } }
end
class MetasController < ApplicationController
def index
Parent.dt_begin = Date.parse(param[:dt_begin])
Parent.dt_end = Date.parse(param[:dt_end])
@parents = Parent.includes(:children).where("children.age = ?", params[:age])
end
end
So this way i get all Parents
even if i dont have Children
created_at between those specified dates.
And the most important part of it i have all objects inside the ActiveRecord.
But be careful because i did messed with cattr_accessor so i have to set everytime before i search for Parents
.
来源:https://stackoverflow.com/questions/15441012/any-possible-way-to-add-parameters-to-on-clause-on-include-left-joins-on-rails