gistfile1.txt

Loading development environment (Rails 3.1.0)
ruby-1.9.2-p180 :001 > 
ruby-1.9.2-p180 :002 >   
ruby-1.9.2-p180 :003 >   HeadType.create
  SQL (12.9ms)  INSERT INTO "head_types" ("created_at", "updated_at") VALUES (?, ?)  [["created_at", Sun, 16 Oct 2011 12:45:08 UTC +00:00], ["updated_at", Sun, 16 Oct 2011 12:45:08 UTC +00:00]]
 => #<HeadType id: 1, created_at: "2011-10-16 12:45:08", updated_at: "2011-10-16 12:45:08"> 
ruby-1.9.2-p180 :004 > HeadType.create
  SQL (0.3ms)  INSERT INTO "head_types" ("created_at", "updated_at") VALUES (?, ?)  [["created_at", Sun, 16 Oct 2011 12:45:10 UTC +00:00], ["updated_at", Sun, 16 Oct 2011 12:45:10 UTC +00:00]]
 => #<HeadType id: 2, created_at: "2011-10-16 12:45:10", updated_at: "2011-10-16 12:45:10"> 
ruby-1.9.2-p180 :005 > p = PressureVessel.create
  SQL (0.5ms)  INSERT INTO "pressure_vessels" ("created_at", "head_one_id", "head_two_id", "updated_at") VALUES (?, ?, ?, ?)  [["created_at", Sun, 16 Oct 2011 12:45:43 UTC +00:00], ["head_one_id", nil], ["head_two_id", nil], ["updated_at", Sun, 16 Oct 2011 12:45:43 UTC +00:00]]
 => #<PressureVessel id: 1, head_one_id: nil, head_two_id: nil, created_at: "2011-10-16 12:45:43", updated_at: "2011-10-16 12:45:43"> 
ruby-1.9.2-p180 :006 > p.head_one_
p.head_one_id                   p.head_one_id_before_type_cast  p.head_one_id_was               p.head_one_type=                
p.head_one_id=                  p.head_one_id_change            p.head_one_id_will_change!      p.head_one_type_loaded?         
p.head_one_id?                  p.head_one_id_changed?          p.head_one_type                 
ruby-1.9.2-p180 :006 > p.head_one_type = HeadType.find(1)
  HeadType Load (0.2ms)  SELECT "head_types".* FROM "head_types" WHERE "head_types"."id" = ? LIMIT 1  [["id", 1]]
 => #<HeadType id: 1, created_at: "2011-10-16 12:45:08", updated_at: "2011-10-16 12:45:08"> 
ruby-1.9.2-p180 :007 > p.head_two_type = HeadType.find(2)
  HeadType Load (0.1ms)  SELECT "head_types".* FROM "head_types" WHERE "head_types"."id" = ? LIMIT 1  [["id", 2]]
 => #<HeadType id: 2, created_at: "2011-10-16 12:45:10", updated_at: "2011-10-16 12:45:10"> 
ruby-1.9.2-p180 :008 > p.save
   (0.3ms)  UPDATE "pressure_vessels" SET "head_one_id" = 1, "head_two_id" = 2, "updated_at" = '2011-10-16 12:46:24.063439' WHERE "pressure_vessels"."id" = 1
 => true 
ruby-1.9.2-p180 :010 > HeadType.first.head_one_pressure_vessels
  HeadType Load (0.1ms)  SELECT "head_types".* FROM "head_types" LIMIT 1
  PressureVessel Load (0.1ms)  SELECT "pressure_vessels".* FROM "pressure_vessels" WHERE "pressure_vessels"."head_one_id" = 1
 => [#<PressureVessel id: 1, head_one_id: 1, head_two_id: 2, created_at: "2011-10-16 12:45:43", updated_at: "2011-10-16 12:46:24">] 
ruby-1.9.2-p180 :011 >