I am generating a report from my ruby on rails app that would run everyday at 7 in the morning.
This report would collect the results from the previous day.
So basically I want query previous day's results to my Mongo collection. This is what I am tried:
logs = Log.where(:comp => comp, :created_at => (Date.today -1))
I got the following error:
BSON::InvalidDocument: Date is not currently supported; use a UTC Time instance instead.
What is the best approach to get the aboce result:
This is the the format of my date in my db:
"created_at" : ISODate("2015-12-02T23:12:38.076Z")
You can do something like this in mongoid:
logs = Log.where(:comp => comp, :created_at.gte => (Date.today -1 ).to_datetime)
Date.to_datetime will default to midnight as shown here:
(Date.today - 1).to_datetime
=> Wed, 30 Mar 2016 00:00:00 +0000
Related
There is task model with attributes when and duration.
create_table "tasks", force: true do |t|
...
t.datetime "when"
t.integer "duration"
...
end
I wrote method for checking if task is active so I can show it on page.
This is active method:
def active?
if (self.when + self.duration) > Time.now
true
end
end
I tried in console to inspect object:
t.when + t.duration
=> Sun, 08 Sep 2013 01:01:00 UTC +00:00
DateTime.now
=> Sun, 08 Sep 2013 01:57:13 +0200
t.active?
=> true
It's true but I entered 1:00 time and 1 minute for duration and I hoped it shouldn't be true.
It seems that when column in database is not saved in correct time zone, so it gives incorrect results. How to solve this issue?
It seems that when column in database is not saved in correct time zone
1) Rails automatically converts times to UTC time before inserting them in the database (which is a good thing), which means the times have an offset of "+0000" . That means if you save a time of 8pm to the database, and your server is located in a timezone with an offset of "+0600", then the equivalent UTC time is 2pm, so 2pm gets saved in the database. In other words, your local server's time is 6 hours ahead of UTC time, which means that when it's 8pm in your server's time zone, it's 2pm in the UTC timezone.
2) When you compare dates, ruby takes the timezone offset into account--in other words ruby converts all times to the same timezone and then compares the times. Here is an example:
2.0.0p247 :086 > x = DateTime.strptime('28-01-2013 08:00:00 PM +6', '%d-%m-%Y %I:%M:%S %p %z')
=> Mon, 28 Jan 2013 20:00:00 +0600
2.0.0p247 :087 > y = DateTime.strptime('28-01-2013 08:20:00 PM +7', '%d-%m-%Y %I:%M:%S %p %z')
=> Mon, 28 Jan 2013 20:20:00 +0700
2.0.0p247 :088 > x < y
=> false
If you just compare the times of the two Datetime objects, x is less than y. However, y has a time of 8:20pm in a timezone that has an offset of +7, which is equivalent to the time 7:20pm in a timezone with an offset of +6. Therefore, y is actually less than x. You need to compare apples to apples, which means you need to mentally compare times that have been converted to the same timezone to get the same results as ruby/rails produces.
3) You can convert Time.now to a UTC time using the rails utc() method:
2.0.0p247 :089 > x = Time.now
=> 2013-09-07 8:00:00 +0600
2.0.0p247 :090 > x.utc
=> 2013-09-07 02:00:00 UTC
That's what ruby does before comparing Time.now to task.when + task.duration
4) You might find it more convenient to create a DateTime object with the time you want using:
DateTime.strptime('28-01-2013 08:00:00 PM +0', '%d-%m-%Y %I:%M:%S %p %z'
Because you are able to specify the offset as zero, you don't have to create a time that anticipates the conversion to UTC time.
Or you can use the change() method, which causes the offset() to change without converting the time:
2.0.0p247 :011 > x = DateTime.now
=> Sun, 08 Sep 2013 00:34:08 +0600
2.0.0p247 :012 > x.change offset: "+0000"
=> Sun, 08 Sep 2013 00:34:08 +0000
ActiveRecord stores timestamps in UTC by default. See How to change default timezone for Active Record in Rails? for changing default time zone.
You can also just use Time#in_time_zone to convert t.when to your timezone, see http://api.rubyonrails.org/classes/ActiveSupport/TimeWithZone.html.
I am in the Central timezone (ENV['TZ'] = America/Chicago) but all my MongoDB entries are stored in UTC format. So if I want to query entries for all of yesterday, I have to overcompensate for the timezone:
tz = 5.hours
d1 = Date.yesterday.at_midnight + tz
d2 = d1 + 1.day
Entry.where(:created_at.gte => d1, :created_at.lt => d2)
I'm pretty sure that this is a major hack, but I'm not sure how to fix this correctly? Should it be on the database end, or in the code. Are there some reading resources that teach how to do this correctly?
Assuming that your Rails application is configured to use UTC (see config.time_zone in config/application.rb) then you should be able to use Time.zone... to build your dates.
I'm in Pacific time, my app is in UTC:
> Time.now
=> 2013-09-10 15:14:46 -0700
> Time.zone.now
=> Tue, 10 Sep 2013 22:14:48 UTC +00:00
I don't know about Mongoid, but ActiveRecord will do this for you:
> Course.where(['created_at < ?', Time.now]).to_sql
=> "SELECT \"courses\".* FROM \"courses\" WHERE (created_at < '2013-09-10 22:16:27.106841')"
> Course.where(['created_at < ?', Time.zone.now]).to_sql
=> "SELECT \"courses\".* FROM \"courses\" WHERE (created_at < '2013-09-10 22:17:03.236353')"
I have a scope that queries for today's calls. Based off of the scope I use it to count the amount of calls for today.
My dates are stored in UTC but rails converts to my local timezone. What I'm trying to do is find all calls between today at 00:00 and 23:59.
Scope:
scope :today, where("DATE(transfer_date) BETWEEN ? AND ?", Time.zone.now.utc.beginning_of_day, Time.zone.now.utc.end_of_day)
irb output: (The call it catches due to UTC)
irb(main):010:0> Call.last.transfer_date
Call Load (0.9ms) SELECT "calls".* FROM "calls" ORDER BY "calls"."id" DESC LIMIT 1
=> Sun, 07 Oct 2012 19:45:00 CDT -05:00
irb(main):011:0>
irb(main):011:0> Call.last.transfer_date.utc
Call Load (1.3ms) SELECT "calls".* FROM "calls" ORDER BY "calls"."id" DESC LIMIT 1
=> 2012-10-08 00:45:00 UTC
I'm trying to figure out how to query only calls that were between 00:00 and 23:59 for today. So far trying to scope with and without utc, zone, etc doesn't work. It keeps pulling the scope based off of UTC which includes the call from yesterday (yesterday if it's formatted with the local timezone).
How can I query between the two times to get the correct output? I'm kind of lost here.
You can use an exclusive range.
scope :today, where(:transfer_date => Date.today...Date.tomorrow)
I was able to compensate for UTC by rewriting my scope as follows:
scope :today, where("transfer_date BETWEEN ? AND ?", Time.zone.now.beginning_of_day, Time.zone.now.end_of_day)
Maybe this is overkill, but I would suggest using a helper method for getting the time range and then querying the db. Something like
# Gets time range for x number timeunits ago
def time_range(unit, timeunit = nil)
if timeunit == "weeks"
now = Time.zone.now.beginning_of_week
elsif timeunit == "months"
now = Time.zone.now.beginning_of_month
else
now = Time.zone.now.beginning_of_day
end
# Ex: time_range(0, "days") --> Get the time range for today between the beginning of today and the beginning of tommorow - 1 second
now - unit.send(timeunit)..now + 1.send(timeunit) - 1.seconds - unit.send(timeunit)
end
will help you to request time ranges. So when you request something like;
time_range(0, "days")
it will return the time range for 0 days ago (today);
Wed, 07 Sep 2016 00:00:00 UTC +00:00..Wed, 07 Sep 2016 23:59:59 UTC +00:00
And then you can simply query the database object and count everything within the range with;
Calls.where(transfer_date: time_range(unit, timeunit)).count
I have a simple Rails 3.b1 (Ruby 1.9.1) application running on Sqlite3. I have this table:
create_table :time_tests do |t|
t.time :time
end
And I see this behavior:
irb(main):001:0> tt = TimeTest.new
=> #<TimeTest id: nil, time: nil>
irb(main):002:0> tt.time = Time.zone.now
=> Mon, 03 May 2010 20:13:21 UTC +00:00
irb(main):003:0> tt.save
=> true
irb(main):004:0> TimeTest.find(:first)
=> #<TimeTest id: 1, time: "2000-01-01 20:13:21">
So, the time is coming back blank. Checking the table, the data looks OK:
sqlite> select * from time_tests;
1|2010-05-03 20:13:21.774741
I guess it's on the retrieval part? What's going on here?
Technically, it's not coming back blank. It comes back as a time with a default date. It returns 2000-01-01 20:13:21 as the time, which is expected.
Rails is doing some magic loading of the data into a Time object and clearing out the date (since you only told it to store the time).
If you want to store the date and time then you need to define the column as a datetime. And conversely, if you wanted just a date you would use date.
So to recap:
date => "2010-12-12 00:00:00"
time => "2000-01-01 13:14:15"
datetime => "2010-12-12 13:14:15"
Suppose I have a standard Post.first.created_at datetime. Can I compare that directly with a datetime in the format 2009-06-03 16:57:45.608000 -04:00 by doing something like:
Post.first.created_at > Time.parse("2009-06-03 16:57:45.608000 -04:00")
Edit: Both fields are datetimes, not dates.
Yes, you can use comparison operators to compare dates e.g.:
irb(main):018:0> yesterday = Date.new(2009,6,13)
=> #<Date: 4909991/2,0,2299161>
irb(main):019:0> Date.today > yesterday
=> true
But are you trying to compare a date to a datetime?
If that's the case, you'll want to convert the datetime to a date then do the comparison.
I hope this helps.
Yes you can compare directly the value of a created_at ActiveRecord date/time field with a regular DateTime object (like the one you can obtain parsing the string you have).
In a project i have a Value object that has a created_at datetime object:
imac:trunk luca$ script/console
Loading development environment (Rails 2.3.2)
>> Value.first.created_at
=> Fri, 12 Jun 2009 08:00:45 CEST 02:00
>> Time.parse("2009-06-03 16:57:45.608000 -04:00")
=> Wed Jun 03 22:57:45 0200 2009
>> Value.first.created_at > Time.parse("2009-06-03 16:57:45.608000 -04:00")
=> true
The created_at field is defined as:
create_table "values", :force => true do |t|
[...]
t.datetime "created_at"
end
N.B. if your field is a date and not a datetime, then you need to convert it to a time:
Post.first.created_at.to_time > Time.parse("2009-06-03 16:57:45.608000 -04:00")
or parse a date:
Post.first.created_at > Date.parse("2009-06-03 16:57:45.608000 -04:00")
otherwise you'll get a:
ArgumentError: comparison of Date with Time failed