In ActiveRecord, how to check if an object property is nil?

Question

Suppose I need to check if a certain property is not set.

I imagine something like this but It doesn't work.

@users = User.find_all_by_role(["role = ?",nil])

I tried some other variants with no luck.

I guess this should be pretty straightforward.

Thank you!

dodecaphonic · Accepted Answer · 2011-02-16 18:20:21Z

1

Using ActiveRecord's pre-3.0 syntax:

@users = User.find(:all, :conditions => { :role => nil })

After 3.0 you can write:

@users = User.where(:role => nil)

answered Feb 16, 2011 at 18:20

dodecaphonic

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Comments

idlefingers · Accepted Answer · 2011-02-16 18:14:49Z

0

Try: @users = User.find(:all, :conditions=>'role is null')

idlefingers

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answered Feb 16, 2011 at 18:09

Paul Lynch

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Thank you, there's a cleaner way above.

idlefingers · Accepted Answer · 2011-02-16 18:16:14Z

0

@users = User.where(:roles => nil).all

There's no need to break into SQL for this.

answered Feb 16, 2011 at 18:16

idlefingers

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