Can someone explain this?
Post.where(:p_date => ((Time.now - 7.days)..(Time.now))).count
-> 4507
Post.where(:p_date => ((Time.now - 7.days).beginning_of_day..(Time.now).end_of_day)).count
-> 4794
While p_date is only date type without time.
Thank you
If p_date is a date column, pass dates into your query
Post.where(p_date: (7.day.ago.to_date .. Date.today)).count
which uses this query
SELECT COUNT(*) FROM `posts` WHERE (`posts`.`p_date` BETWEEN '2016-09-08' AND '2016-09-15')
If you pass in time objects, the database will automatically compare against 0:00:00 time (at least on mysql and postgres) which is where you get your discrepancy from.
Related
I have a document that has been generated, say, on 2017-10-03 15:02:47.
Then I have this Rails/SQL query (it doesn't matter if I run it through Rails or straight through the SQL console, the results are the same):
SELECT * FROM table where needed_column <= '2017-10-03';
This query would not return me the document that has been generated on 2017-10-03 15:02:47. If I do run, though, this query:
SELECT * FROM table where needed_column <= '2017-10-03 23:59:59';
Then I get the needed document (generated on 2017-10-03 15:02:47).
To solve this issue, I can manually add the time to the query (23:59:59), but it's not a very elegant solution.
I am using Rails 5, AR, PostgreSQL - is there a better way to solve this problem than to manually add the time stamp to the query?
Thank you
Your needed_column is probably saving timestamps (Date and Time). As you already figured it out you need to compare it with another timestamp or cast needed_column using ::date
Model.where("needed_column::date <= '2017-10-03'")
This will generate:
SELECT table.* FROM table WHERE (needed_column::date <= '2017-10-03')
Try this in Rails:-
Model.where(needed_column: [Time.now.at_beginning_of_day, Time.now.end_of_day])
Or as sql query:-
SELECT * FROM table_name WHERE needed_column BETWEEN '2017-10-09 00:00:00 UTC' AND '2017-10-09 23:59:59 UTC'
SPEC
I need to pick all rooms that don't have a single day with saleable = FALSE in the requested time period(07-09 ~ 07-19):
I have a table room with 1 row per room.
I have a table room_skus with one row per room and day (complete set for the relevant time range).
The column saleable is boolean NOT NULL and date is defined date NOT NULL
SELECT id
FROM room r
WHERE NOT EXISTS (
SELECT 1
FROM room_skus
WHERE date BETWEEN '2016-07-09' AND '2016-07-19'
AND room_id = r.id
AND NOT saleable
GROUP BY 1
);
The above SQL query is working, but I wonder how could I translate it into Rails ORM.
Let's say you have array of room_ids called room_ids:
needed_room_ids = room_ids - RoomSku.where(room_id: room_ids, date: '2016-07-09'..'2016-07-19', sealable: false).pluck(:room_id)
If your model of room_sku is called RoomSku
Updated version:
room_ids = Room.all.select { |record| record.room_skus.present? }.map(&:id)
And then:
needed_room_ids = room_ids - RoomSku.where(room_id: room_ids, date: '2016-07-09'..'2016-07-19', sealable: false).pluck(:room_id)
It won't be one query, but you avoid plain SQL like this.
I don't have any project here to test something like it, but it should work:
Room.where.not(id: RoomSku.where(date: DateTime.parse('2016-07-09').strftime("%Y-%m-%d")..DateTime.parse('2016-07-19').strftime("%Y-%m-%d"), saleable: false).pluck(:room_id))
I hope it helps!
Background:
Writing a Ruby on Rails app that is connect to MS SQL DB(don't ask why, its something I cant get around), the DB is quiet large and can have up to 2/3 million rows.
There is one main columns that matter for me at the moment and that is 'TimeUTC' and the table is called ApplicationLog and the query will be in the ApplicationLogController.
Problem:
I want to write a query that i can pass in two dates and it will group all the records by day using the 'TimeUTC' column and gives me a total of all the records for those days in between those two dates.
I have the SQL Query:
DECLARE #StartDate DateTime = '2014-01-04 00:00:00'
DECLARE #EndDate DateTime = '2014-02-04 23:59:59'
select (dateadd(DAY,0, datediff(day,0, TimeUtc))) as [DATE], count(*)
from applicationlog (nolock)
where TimeUtc between #StartDate and #EndDate
group by dateadd(DAY,0, datediff(day,0, TimeUtc))
order by [DATE] desc
I try starting with something like this:
#results = ApplicationLog.select((dateadd(DAY,0, datediff(day,0, TimeUtc)) as [date], count(*)).
group(dateadd(DAY,0, datediff(day,0, TimeUtc))).order(date desc)
Now I am a newbie at this so I could be so far off the track its not funny, but any help would be great. Am I even going about this the right way, is there a better way??
Try with the following code, which uses Arel code with some SQL embedded.
class ApplicationLog < ActiveRecord::Base
def self.between(range)
columns = Arel.sql('dateadd(DAY,0,datediff(day,0,TimeUtc)) as date, COUNT(*)')
conditions = arel_table['TimeUTC'].in(range)
query = arel_table.project(columns).where(conditions).group([1]).order('date desc')
ActiveRecord::Base.connection.execute(query.to_sql)
end
end
Then use ApplicationLog.between(1.week.ago..Time.now).
I'm trying to figure out how to do a query where created_at.year == a given year, and created_at.month equals a given month.
However I can't figure out what I'm doing wrong.
Model.where("'created_at.month' = ? AND 'created_at.year' = ?", 7,2013)
results in nothing being shown.
However when I try Model.first.created_at.month ==7 and
Model.first.created_at.year ==2013 I get true for both.
Therefore theoretically my query should be at least be returning my first record.
Anyone know what I'm doing wrong or any alternative way to find records created on specific months?
Note that in my views the month / year will be parameters but for the purposes of this example I used actual values.
using ruby 1.9.3
rails 3.2.13
You can use the extract SQL function, that will extract the month and year of the timestamp:
Model.where('extract(year from created_at) = ? and extract(month from created_at) = ?', '2013','7')
This query should give you the desired result.
created_at is a timestamp; it is not a set of discrete fields in the database. created_at.year and such don't exist in your DB; it's simply a single timestamp field. When you call #model.created_at.year, Rails is loading the created_at field from the database, and creating a Time object from it, which has a #year method you can call.
What you want is to query on a range of dates:
Model.where("created_at >= ? and created_at < ?", Time.mktime(2013, 7), Time.mktime(2013, 8))
This will find any Model with a created_at timestamp in July 2013.
I have in my db a attribute where i save the record creation date.
The saved date has this format:
2013/06/18 19:03:24
I need to search only for date and i am not interested the time
I have try in this mode but it's doesn't work:
Report.find_all_by_created_at("2013-06-18").each do |r| %>
[...]
end
Given that created_at is a Rails generated column you can't really and just for created at date. Reason for that is in database created_at is saved as timestamp (or Datetime) so records created on 18th of June may have values from 2013-06-18 00:00:00 to 2013-06-18 23:59:59.
So, if you'd like to select all objects created on specific day you should do something like
Report.where('created_at >= ? AND created_at <= ?, Date.new(2013,6,18).beginning_of_day, Date.new(2013,6,18).end_of_day)
You can pass a range to where:
date = Date.new(2013,6,18)
Report.where(created_at: date.beginning_of_day..date.end_of_day)
This creates a SQL statement like:
SELECT `reports`.* FROM `reports` WHERE `reports`.`created_at` BETWEEN '2013-06-18 00:00:00' AND '2013-06-18 23:59:59'
Probably not the best solution but you could do:
Report.where("created_at >= ? and created_at < ?","2013-06-18","2013,06-19").each do |r|
[...]
end
It looks like you are collecting it as a DateTime and you would probably be able to use the to_date() method to change it to a Date object which would be searchable.
http://api.rubyonrails.org/classes/DateTime.html#method-i-to_date
you can use like matcher in sql query
Report.where("created_at LIKE '2013-06-18%'")
or look at the Squeel gem it can call SQL functions in ruby like syntax then you could use something thati will generate query with
WHERE cast(created_at as date) = '2013-06-18'