CODEWITHSUNDEEP
sqlruby-on-railsrubypostgresqlactiverecord
Nikos4Life
Nikos4Life

Reputation: 101

ActiveRecord's finding methods? Help to join models

I have two models already created and properly working: 

class Track < ActiveRecord::Base
    has_many :grand_prixes
end

class GrandPrix < ActiveRecord::Base
    belongs_to :track
end

My database schema is:

create_table "tracks", force: :cascade do |t|
    t.string   "track_name"
    t.string   "description"
    t.string   "country"
    t.string   "lenght"
    t.integer  "pit_boxes"
    t.datetime "created_at",    null: false
    t.datetime "updated_at",    null: false
    t.string   "ac_track_name"
  end
add_index "tracks", ["ac_track_name"], name: "index_tracks_on_ac_track_name"




create_table "grand_prixes", force: :cascade do |t|
    t.datetime "gp_date"
    t.integer  "max_slots"
    t.integer  "event_id"
    t.integer  "track_id"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end


  add_index "grand_prixes", ["track_id"], name: "index_grand_prixes_on_track_id"

I am able to can find the GrandPrix that are associated with a Track by id, but I want to find the GrandPrix in the table by the id of the track previously searched by track's name (a variable that comes from another site):

GrandPrix.where (track_id: 2)

This works and returned the GP I want.

I want to search by name:

GrandPrix.where (Track.name = "thenameIwant")

and to return my id:

SELECT id FROM WHERE tracks tracks.name LIKE 'thenameIwant';

Then it would be something like this:

GrandPrix.where (Track.id = SELECT id FROM WHERE tracks tracks.name LIKE 'thenameIwant')

Upvotes: 3

Views: 50

Answers (1)

Anthony E
Anthony E

Reputation: 11235

Use the joins keyword to join the two relations: 

GrandPrix.joins(:track).where(tracks: {name: "thenameIwant"})

Note the plural "tracks" in the where clause since your table name is "tracks"

Upvotes: 1

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