Remove update_attribute.

[steveklabnik]

Historically, update_attribute and update_attributes are similar, but
with one big difference: update_attribute does not run validations.
These two methods are really easy to confuse given their similar
names. Therefore, update_attribute is being removed in favor of
update_column.

See the thread on rails-core here:
https://groups.google.com/forum/?fromgroups#!topic/rubyonrails-core/BWPUTK7WvYA

[mhuggins]

Nice! Always found this confusing and questioned the reasoning behind the difference in the first place.

[laserlemon]

I don't think that update_column and update_attribute are interchangeable. Validations are a major difference between update_attribute and update_attributes but as I understand, update_attribute still goes through AR's normal save lifecycle including dirty tracking and callbacks while update_column does not.

[fxn]

Right, nobody claims that. Those differences are explained in the deprecation warning in 3.2, and in the CHANGELOG.

[steveklabnik]

#6739 is the one with the warning. :)

[dideler]

I'm confused. The update_attribute method is still documented for Rails 4 and it works when I try it in console. I see a lot of places saying that this method has been removed (e.g. the Rails community style guide). I'm guessing it's been re-added since?

[rafaelfranca]

It was not removed yet. In fact it was but we reverted to better evaluate its usage.