2.0.0-p247 :001 > EventDate
=> EventDate(id: integer, title: string, allDay: boolean, start: time, end: time, created_at: datetime, updated_at: datetime, event_id: integer)
2.0.0-p247 :002 > ex = EventDate.find(2)
EventDate Load (8.4ms) SELECT "event_dates".* FROM "event_dates" WHERE "event_dates"."id" = ? LIMIT 1 [["id", 2]]
=> #<EventDate id: 2, title: "Work all day", allDay: true, start: "2000-01-01 07:00:00", end: nil, created_at: "2013-09-10 09:02:06", updated_at: "2013-09-11 02:15:09", event_id: 1>
2.0.0-p247 :004 > ex.start = Time.local(2013, 9, 20)
=> 2013-09-20 00:00:00 -0700
2.0.0-p247 :005 > ex.save
(0.1ms) begin transaction
SQL (2.0ms) UPDATE "event_dates" SET "start" = ?, "updated_at" = ? WHERE "event_dates"."id" = 2 [["start", 2013-09-20 00:00:00 -0700], ["updated_at", Wed, 11 Sep 2013 03:26:39 UTC +00:00]]
(0.6ms) commit transaction
=> true
2.0.0-p247 :006 > ex
=> #<EventDate id: 2, title: "Work all day", allDay: true, start: "2013-09-20 00:00:00", end: nil, created_at: "2013-09-10 09:02:06", updated_at: "2013-09-11 03:26:39", event_id: 1>
2.0.0-p247 :007 > EventDate.find(2)
EventDate Load (0.2ms) SELECT "event_dates".* FROM "event_dates" WHERE "event_dates"."id" = ? LIMIT 1 [["id", 2]]
=> #<EventDate id: 2, title: "Work all day", allDay: true, start: "2000-01-01 07:00:00", end: nil, created_at: "2013-09-10 09:02:06", updated_at: "2013-09-11 03:26:39", event_id: 1>
这是我的rails控制台的输出。如果您按照代码，您将看到我更新了id = 2的EventDate的开始字段。我保存它，当我检索相同的元素时，它不反映更改。但是，更改像标题这样的字段可以正确保存。