Might be a somewhat specific situation. And I kinda know how to do it in PHP/MySQL. But I was wondering if there was a faster way to do the following scenario:
A user has activities with a start- and end_date. (The activity starts at 12-10-2013 12:00:00 and ends at 12-10-2013 12:15:00 for example.)
Whenever the user creates a new activity. I want to check all the activities the user is part of(user has_many: activities) and see if none of the dates intersect with the date given for the new activity.
Since I'm pretty new to Rails I really don't know where to start searching for date comparisons and all...
Thanks in advance
An overlap is defined as another activity for which the end date is greater than or equal to the new activity's start date, and for which the start date is less than or equal to the new activity's end date.
Since you only want to detect whether such a record already exists, an appropriate test would be:
if Activity.where("starts_at <= ?" , new_activity_end_date ).
where("ends_at >= ?" , new_activity_start_date).
exists?
You can use regular comparators for date/times in Ruby (ie: >, < and ==).
Something like the following should do what you are looking for:
if current_user.activities.where("(starts_at <= ? AND ends_at >= ?) OR (starts_at >= ? AND starts_at <= ?)", start_datetime, start_datetime, start_datetime, end_datetime).count
# There exist activities that fall between start_datetime and end_datetime
else
# There exist no such activities
end
(starts_at <= start_datetime AND ends_at >= start_datetime) checks whether an event starts before and ends after start_datetime.
(starts_at >= start_datetime AND starts_at <= end_datetime) checks whether an event starts between start_datetime and end_datetime.
We must check that all this three kinds of intersection do not happen:
our activity must not happen within another activity
our activity must not start before another ends
our activity must not ends after another starts
We can do that using something like this:
class Activity < ActiveRecord::Base
validate :must_not_be_intersected
def intersected?
params = {
:start => start_date,
:end => end_date
}
Activity::where('start_date <= :start AND end_date >= :end', params)
.where('(start_date >= :start AND start_date <= :end) OR (end_date >= :start AND end_date <= :end)', params)
.exists?
end
private
def must_not_be_intersected
errors.add :base, 'Other task running on the same period' if intersected?
end
end
Related
I am making an appointment, scheduling API. I have many starttime and endtime pairings in DateTime format. I need to be sure that when I create a new appointment that times do not overlap with previous ones. What I mean is that if I have an appointment starting at 7/4/15 9:00 and ending at 7/4/15 13:00 I want to make a validation so that I can't make a new appintment starting at 7/4/15 10:00 ending at 7/4/15 12:00. I want to compare all the key value pairs to make sure the new one doesn't fall inside that range. Any ideas how I can do this?
An overlap happens when you have an a appointment that starts before this appointment ends, and ends after this one starts. If there are no appointments that fit that criteria, there are no overlaps.
Note that you need to also consider the special case that searching for appointments will find one overlap but it's the appointment you're currently editing, so you can ignore that one.
class Appointment < ActiveRecord::Base
validate :no_overlapping_appointments
def no_overlapping_appointments
overlaps = Appointment.where('start_time <= ? AND end_time >= ?', end_time, start_time)
return if overlaps.empty?
return if overlaps.count == 1 && overlaps.first.id == id
errors.add(:start_time, "This appointment overlaps others")
end
end
class Appointment < ActiveRecord::Base
validate :duration_not_overlap
private
def duration_not_overlap
verify_time(:starttime)
verify_time(:endtime)
end
# attr is :starttime | :endtime
def verify_time(attr)
errors[attr] << 'overlap' if Appointment.where(user_id: user_id, attr => (starttime..endtime)).exists?
end
end
There are many questions relate to rails date range problem but mine is a little more complicated.
I have two models: house and booking. A House has_many bookings. A Booking has two attributes in date format: check_in and check_out.
What I want to achieve: Giving a valid date range, show all houses that are available during this range. In detail:
The start date of the range should not be in any booking.
The end date of the range should not be in any booking.
There should not be any booking between the start and the end.
Can this be done using the rails scope?
UPDATE:
I found the code below that can check scope date interval that overlaps.
named_scope :overlapping, lambda { |interval| {
:conditions => ["id <> ? AND (DATEDIFF(start_date, ?) * DATEDIFF(?, end_date)) >= 0", interval.id, interval.end_date, interval.start_date]
}}
How can I transfer this to my problem?
scope :overlapping, (lambda do |start_date, end_date|
House.includes(:bookings).where("bookings.check_in < ? AND bookings.check_out > ?",
start_date, end_date).references(:bookings).uniq
end)
I went ahead and deleted the >= and <= operators in favor of > and < to explicitly show these bookings being outside of the given range, but you can adjust them per your needs!
Update
Changed query to use #includes instead of #joins, since we're querying the attached table.
Yes it is possible to have this query through scope. Put this scope in house model.
scope :overlapping, -> (start_date, end_date) {
includes(:bookings).where('bookings.check_in < ? AND bookings.check_out > ?',
start_date.to_date, end_date.to_date)
}
And call as House.overlapping('2015-07-01', '2015-07-09')
I am creating a filtering partial view, where user can pick a from-date and a to-date using a calendar. These dates are used then within model scope to perform SQL Where clause in database query. If a user does not pick one of dates, the default value should be assigned: minimal available date for from and maximal for to.
unless params[:from].blank? and params[:to].blank?
from = begin Date.parse(params[:from]) rescue ??? end
to = begin Date.parse(params[:to]) rescue ??? end
#model_instances = #model_instances.start_end from, to
end
(...)
scope :start_end, -> (start_date, end_date) { where('(:start_date <= "from" AND "from" <= :end_date ) OR' +
'(:start_date <= "to" AND "to" <= :end_date ) OR' +
'("from" <= :start_date AND :end_date <= "to")',
{start_date: start_date, end_date: end_date}) }
The from and to model Date attributes are also database fields in related table.
In Rails, Date class has a family of methods beginning_of (day, week, month, etc.), but there are no methods such beginning_of_time, end_of_time, Date.min, Date.max.
Are there any methods to obtain the minimal and maximal dates?
You could skip the condition on start and end dates if no params is given:
if params[:from].present? and params[:to].present?
#model_instances.start_end(params[:from], params[:to])
end
And then you will get results not depending on dates since no from and/or end dates have been filled.
You could compare ranges of dates to your model's values and setup default values if params not passed.
#setup default if desired, or you can skip if params are blank
from = params[:from] || default_from
to = params[:to] || default_to
#model_instances.start_end(from, to)
and your scope would look something like this if you used date ranges for activerecord
scope :start_end, ->(start_date, end_date){where(from: start_date..end_date, to:start_date..end_date)}
I'm trying to find records whose start and end date range over a particular date. Date is random and :start_date and :end_date are attributes of the prices entity.
date = Time.now
record_i_want = Price.where(date => :start_date .. :end_date)
Thank you.
You can simply do
Price.where(:date => start_date..end_date)
This will result in the following SQL( for start and end dates - '2014-03-27', '2014-03-28')
SELECT `prices`.* FROM `prices` WHERE (`prices`.`date` BETWEEN '2014-03-27' AND '2014-03-28')
EDIT:
Realized that this is the query you are looking for. Thanks, Coenwulf for pointing it out
Price.where(['start_date < ? AND end_date > ?', date, date])
You want to select rows where your date is greater than the start_date and less than the end_date. You can specify the appropriate SQL where clause parameterized in your call to where like so:
Price.where([":date >= start_date AND :date <= end_date", {date: Date.today})
That will give you all the prices that match. If you know you'll get only one you can get it by calling first.
Price.where([":date >= start_date AND :date <= end_date", {date: Date.today}).first
Make any appropriate adjustment to the >= and <= if you want to exclude the start_date and/or the end_date from the results. If for example the Price is valid starting on the start_date but isn't valid through the end_date you can change the clause to:
":date >= start_date AND :date < end_date"
This should work:
def get_record_by_date(date)
Price.where([start_date.to_i < date.to_i] && [end_date.to_i > date.to_i])
end
I need to validate two dates in date time format that come from create new record form. Right now the form has drop downs for year, date, month, hour, minute. In the controller, I need to validate that the start date is not greater than end date and it will not let me compare it using the params[:start_date] > params[:end_date].
How can I properly validate that the start date is not larger than the end date when adding a new record to the database, I should be doing this in the model but I cannot figure out how you do it. Does anyone here has any examples I can look from?
Add custom validation to your model to verify that the start date is less than the end date. Something like this would work:
# app/models/my_model.rb
validate :dates_in_order
def dates_in_order
errors.add(:start_date, "must be before end time") unless start_date < end_date
end
#some_model.rb
before_create -> {
errors.add(:base, "Start date cannot be later than end date.") if start_date > end_date
}
Not what you're asking for, but may also be a way to handle this. People sometimes don't read the labels so closely.
before_create :confirm_dates_in_order
def confirm_dates_in_order
start_date, end_date = end_date, start_date if start_date > end_date
end