ActiveRecord: milliseconds aren't taken into account when using a where clause

Question

I\'m working on a project with a rails api and an iOS client, using the updated_at field as the reference to detect modifications on the server that happened after the last

Answer 1

If you're using the ISO8601 standard you can use .iso8601(10). Don't know why but it rounds to seconds by default.

Answer 2

Try

Model.where("updated_at > ?", last_update.strftime("%Y-%m-%dT%H:%M:%S.%N%z"))

You can also set this format as the standard format for DateTime in databases by setting (i.e. in an initiallizer):

Time::DATE_FORMATS[:db]= '%Y-%m-%dT%H:%M:%S.%N%z'

then your original query works again:

Model.where("updated_at > ?", last_update)

See the Rails API for DateTime.to_s (aka .to_formated_s)