Rails `where` for time less than queries
arel, date, mysql, ruby-on-rails, sql
Solution
Edit 2 5/9/20
If you are using Ruby 2.6 you can do this with endless ranges and in Ruby 2.7 you can use begin-less ranges.
E.g.:
# Ruby >= 2.6
User.where(last_deposit: 10.days.ago..)
generates
SELECT "users".* FROM "users" WHERE "user"."last_deposit" >= '2020-04-29 21:58:39.109419'"
and
# Ruby >= 2.7
User.where(last_deposit: ..10.days.ago)
generates
SELECT "users".* FROM "users" WHERE "users"."last_deposit" <= '2020-04-29 22:01:05.582055'
Edit
This is now possible in Rails 5!
User.where(last_deposit: 10.days.ago..DateTime::Infinity.new)
will generate the SQL
SELECT `users`.* FROM `users` WHERE (`users`.`last_deposit` >= '2018-06-30 17:08:54.130085').
Original (and Rails < 5) Answer
It does not appear as if there is a way to use basic `where` hash syntax to generate a greater than or less than query for timestamps. The simplest and most readable way is outlined in my question under `Current Simple Solution`.
Another way to do it makes use of ARel but you have to make some less commonly seen calls. First you can get a handle to the AR class' ARel table, access the column, pass the result of the greater than `gt`, greater than or equal to `gteq`, less than `lt`, and/or less than or equal to `lteq` method with an argument to `where`.
In the situation above this would be done like:
last_deposit_column = User.arel_table[:last_deposit]
last_deposit_over_ten_days_ago = last_deposit_column.gteq(10.days.ago)
User.where(last_deposit_over_ten_days_ago)
Problem
Setup Rails' `where` method can take a range in a hash to generate a query that will search for a value that is within the range. For example: ``` User.where(cash_money: 10..1000) #=> SELECT `users`.* FROM `users` WHERE (`users`.`cash_money` BETWEEN 10 AND 1000) ``` This can also be used with timestamps like ``` User.where(last_deposit: 10.days.ago..1000.days.ago) #=> SELECT `users`.* FROM `users` WHERE (`users`.`last_deposit` BETWEEN '2014-05-19 14:42:36' AND '2011-09-02 14:42:36') ``` I've found that you can do a simple less than or greater than with numbers using the hash syntax like this ``` User.where(cash_money: 10..Float::INFINITY) #=> SELECT `users`.* FROM `users` WHERE (`users`.`cash_money` >= 10) ``` and the same can be done with `-Float::INFINITY` for less than queries. Question Is there a way to do this with timestamps so I can get a query like the following? ``` SELECT `users`.* FROM `users` WHERE (`users`.`last_deposit` >= '2014-05-19 14:42:36') ``` I cannot use `Float::INFINITY` or `Date::Infinity` with a range as they both error with `ArgumentError: bad value for range`. Current Simple Solution ``` User.where('`users`.`last_deposit` >= ?', 10.days.ago) ``` will generate the same SQL but if this can be done with objects other than strings, I'd like to do so. Potential (Meh) Answer This is kind of lousy but it could be done with ranges using `Time.at(0)` and `Time.at(Float::MAX)`. I have a feeling these could result in equally lousy SQL queries though.