Check date is not null ? (rails, arel)

Question

How do you check in Rails3 (with or without Arel) if a date is filled in (as in, not null)? I know you can do it by using:

obj.where('PLANNED IS NOT NULL')

but is it possible without using SQL?

// SQL 
SELECT * FROM projecttasks WHERE planned IS not null

I tried:

# all tasks which have a date
tasks = Projecttask.where(:planned => !nil)

or

# all task with no planned date (sql: is null)
Projecttask.where(:planned => nil)

But that doesn't work. In general, how you can do a 'where' on NULL and NON NULL columns.

Thanks.

Answer 1

You can check this similar question for the answer. The answer by Ryan Bigg is what I'm guessing you are looking for.

Rails where condition using NOT NULL