Question

好的，所以我有一个26天前创建的记录，但是当我与2.days.ago进行比较时，它告诉我错误我不知道为什么，我已经在这里等了3个小时尝试了几个事情和做很多谷歌搜索似乎没有任何作用这是我的终端代码示例

2.1.1 :066 > Ticket4Midnite.first.created_at Ticket4Midnite Load (0.3ms) SELECT "ticket4_midnites".* FROM "ticket4_midnites" LIMIT 1 => Fri, 04 Jul 2014 19:10:00 UTC +00:00 2.1.1 :067 > helper.time_ago_in_words(Ticket4Midnite.first.created_at) Ticket4Midnite Load (0.3ms) SELECT "ticket4_midnites".* FROM "ticket4_midnites" LIMIT 1 => "26 days" 2.1.1 :068 > Ticket4Midnite.first.created_at>=2.days.ago Ticket4Midnite Load (0.3ms) SELECT "ticket4_midnites".* FROM "ticket4_midnites" LIMIT 1 => false 2.1.1 :069 >

我的表数据类型的示例我正在使用postgresql数据库

Table "public.ticket4_midnites" Column | Type | Modifiers ---------------------------+-----------------------------+--------------------------------------------------------------- id | integer | not null default nextval('ticket4_midnites_id_seq'::regclass) company | character varying(255) | surfaceLocation | character varying(255) | DownholeLocation | character varying(255) | Field | character varying(255) | SiteSupervisor | character varying(255) | SafeWorkPermit | character varying(255) | Date | character varying(255) | DayNightTour | character varying(255) | RigNumber | character varying(255) | ReportNumber | character varying(255) | returnToBase | boolean | StayinCamp | boolean | prejobsafety | boolean | rigWalkAroundDone | boolean | AirKillSafetyCheck | boolean | FunctionTestBOP | boolean | DrillHeadwhileTappingRods | boolean | BOPDrillSatisfactory | boolean | created_at | timestamp without time zone | not null updated_at | timestamp without time zone | not null username | character varying(255) | status | character varying(255) | Indexes: "ticket4_midnites_pkey" PRIMARY KEY, btree (id)

如果您需要任何其他信息，我将提供任何帮助将不胜感激!!

Answer 1

像弗雷德里克·张在评论中指出的那样，你误解了Ticket4Midnite.first.created_at>=2.days.ago的作用。

通过拆分代码，您可以看到它实际上在做什么看看它是这样的：

(Ticket4Midnite.first.created_at) >= (2.days.ago)

这只是比较时间戳。

(July 4th @ Some time) >= (July 28th @ current time)

这是问第一个时间戳是否比两天前更早的时间。

由于它不是，它会返回false。

另一个例子，来自ruby-docs for Time：

t1 = Time.new(2010)
t2 = Time.new(2011)

t1 == t2 #=> false
t1 == t1 #=> true
t1 <  t2 #=> true
t1 >  t2 #=> false

大于和小于时间的比较是在问哪个时间是第一次。

因此，对于您的情况，只需翻转比较的方向，它就会按预期运行。

时间比较的意外行为

1 个答案: