Re: [Rails-core] update_columns doesn't support an empty hash
Are not both cases invalid input? Why should we accept empty hashes?
On Thu, May 7, 2015 at 2:14 PM Michael Mahemoff wrote:
> The following will return an error:
>
> > Post.first.update_columns({})
> ArgumentError: Empty list of attributes to change
>
> I think that's surprising, because I see update_columns as an analogue to
> update_attributes, just without callbacks happening. An empty hash for the
> latter is fine:
>
> > Post.first.update_attributes({})
> true
>
> So shouldn't update_columns support an empty hash too? In the rare cases
> where callbacks should be avoided and this is needed, it would save having
> to make a special-case check to prevent the error.
>
> --
> You received this message because you are subscribed to the Google Groups
> "Ruby on Rails: Core" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to rubyonrails-core+unsubscr...@googlegroups.com.
> To post to this group, send email to rubyonrails-core@googlegroups.com.
> Visit this group at http://groups.google.com/group/rubyonrails-core.
> For more options, visit https://groups.google.com/d/optout.
>
--
You received this message because you are subscribed to the Google Groups "Ruby
on Rails: Core" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to rubyonrails-core+unsubscr...@googlegroups.com.
To post to this group, send email to rubyonrails-core@googlegroups.com.
Visit this group at http://groups.google.com/group/rubyonrails-core.
For more options, visit https://groups.google.com/d/optout.
Re: [Rails-core] update_columns doesn't support an empty hash
Basically because http://en.wikipedia.org/wiki/Null_Object_pattern. It's
often the case that systems have to deal with "N" possible changes, where N
is between 0 and 1. e.g. I might have a procedure to gradually build up a
list of things to change, starting with {} and appending to it if certain
conditions are met. It wouldn't be an exceptional situation if none of
those conditions are met.
On Thursday, 7 May 2015 18:24:50 UTC+1, Rafael Mendonça França wrote:
>
> Are not both cases invalid input? Why should we accept empty hashes?
>
> On Thu, May 7, 2015 at 2:14 PM Michael Mahemoff > wrote:
>
>> The following will return an error:
>>
>> > Post.first.update_columns({})
>> ArgumentError: Empty list of attributes to change
>>
>> I think that's surprising, because I see update_columns as an analogue to
>> update_attributes, just without callbacks happening. An empty hash for the
>> latter is fine:
>>
>> > Post.first.update_attributes({})
>> true
>>
>> So shouldn't update_columns support an empty hash too? In the rare cases
>> where callbacks should be avoided and this is needed, it would save having
>> to make a special-case check to prevent the error.
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "Ruby on Rails: Core" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to rubyonrails-co...@googlegroups.com .
>> To post to this group, send email to rubyonra...@googlegroups.com
>> .
>> Visit this group at http://groups.google.com/group/rubyonrails-core.
>> For more options, visit https://groups.google.com/d/optout.
>>
>
--
You received this message because you are subscribed to the Google Groups "Ruby
on Rails: Core" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to rubyonrails-core+unsubscr...@googlegroups.com.
To post to this group, send email to rubyonrails-core@googlegroups.com.
Visit this group at http://groups.google.com/group/rubyonrails-core.
For more options, visit https://groups.google.com/d/optout.
Re: [Rails-core] update_columns doesn't support an empty hash
Bah I mean "N is between 0 and " (rather than 1 and ).
On Thursday, 7 May 2015 18:46:51 UTC+1, Michael Mahemoff wrote:
>
> Basically because http://en.wikipedia.org/wiki/Null_Object_pattern. It's
> often the case that systems have to deal with "N" possible changes, where N
> is between 0 and 1. e.g. I might have a procedure to gradually build up a
> list of things to change, starting with {} and appending to it if certain
> conditions are met. It wouldn't be an exceptional situation if none of
> those conditions are met.
>
> On Thursday, 7 May 2015 18:24:50 UTC+1, Rafael Mendonça França wrote:
>>
>> Are not both cases invalid input? Why should we accept empty hashes?
>>
>> On Thu, May 7, 2015 at 2:14 PM Michael Mahemoff
>> wrote:
>>
>>> The following will return an error:
>>>
>>> > Post.first.update_columns({})
>>> ArgumentError: Empty list of attributes to change
>>>
>>> I think that's surprising, because I see update_columns as an analogue
>>> to update_attributes, just without callbacks happening. An empty hash for
>>> the latter is fine:
>>>
>>> > Post.first.update_attributes({})
>>> true
>>>
>>> So shouldn't update_columns support an empty hash too? In the rare cases
>>> where callbacks should be avoided and this is needed, it would save having
>>> to make a special-case check to prevent the error.
>>>
>>> --
>>> You received this message because you are subscribed to the Google
>>> Groups "Ruby on Rails: Core" group.
>>> To unsubscribe from this group and stop receiving emails from it, send
>>> an email to rubyonrails-co...@googlegroups.com.
>>> To post to this group, send email to rubyonra...@googlegroups.com.
>>> Visit this group at http://groups.google.com/group/rubyonrails-core.
>>> For more options, visit https://groups.google.com/d/optout.
>>>
>>
--
You received this message because you are subscribed to the Google Groups "Ruby
on Rails: Core" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to rubyonrails-core+unsubscr...@googlegroups.com.
To post to this group, send email to rubyonrails-core@googlegroups.com.
Visit this group at http://groups.google.com/group/rubyonrails-core.
For more options, visit https://groups.google.com/d/optout.
Re: [Rails-core] update_columns doesn't support an empty hash
It makes sense to me, you get passed a hash with the attributes to update, which could be none. This is a no-op edge-case similar to append an empty list to a list, etc., and could have use cases where the hash is built programatically. The implementation generally uses iterators, which is the normal way to support these edge-cases with no explicit handling, maybe the exception is raised by update_all(attributes) https://github.com/rails/rails/blob/master/activerecord/lib/active_record/persistence.rb#L312 ? -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-core+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-core@googlegroups.com. Visit this group at http://groups.google.com/group/rubyonrails-core. For more options, visit https://groups.google.com/d/optout.
Re: [Rails-core] update_columns doesn't support an empty hash
And what happen if users expect N to be between 1 and and we
silently do nothing when 0 is sent to these methods?
In my opinion if you don't have changes to be made in the database, just
don't call the method.
On Thu, May 7, 2015 at 2:47 PM Michael Mahemoff wrote:
> Bah I mean "N is between 0 and " (rather than 1 and ).
>
>
> On Thursday, 7 May 2015 18:46:51 UTC+1, Michael Mahemoff wrote:
>>
>> Basically because http://en.wikipedia.org/wiki/Null_Object_pattern. It's
>> often the case that systems have to deal with "N" possible changes, where N
>> is between 0 and 1. e.g. I might have a procedure to gradually build up a
>> list of things to change, starting with {} and appending to it if certain
>> conditions are met. It wouldn't be an exceptional situation if none of
>> those conditions are met.
>>
>> On Thursday, 7 May 2015 18:24:50 UTC+1, Rafael Mendonça França wrote:
>>>
>>> Are not both cases invalid input? Why should we accept empty hashes?
>>>
>>> On Thu, May 7, 2015 at 2:14 PM Michael Mahemoff
>>> wrote:
>>>
The following will return an error:
> Post.first.update_columns({})
ArgumentError: Empty list of attributes to change
I think that's surprising, because I see update_columns as an analogue
to update_attributes, just without callbacks happening. An empty hash for
the latter is fine:
> Post.first.update_attributes({})
true
So shouldn't update_columns support an empty hash too? In the rare
cases where callbacks should be avoided and this is needed, it would save
having to make a special-case check to prevent the error.
--
You received this message because you are subscribed to the Google
Groups "Ruby on Rails: Core" group.
To unsubscribe from this group and stop receiving emails from it, send
an email to rubyonrails-co...@googlegroups.com.
To post to this group, send email to rubyonra...@googlegroups.com.
Visit this group at http://groups.google.com/group/rubyonrails-core.
For more options, visit https://groups.google.com/d/optout.
>>> --
> You received this message because you are subscribed to the Google Groups
> "Ruby on Rails: Core" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to rubyonrails-core+unsubscr...@googlegroups.com.
> To post to this group, send email to rubyonrails-core@googlegroups.com.
> Visit this group at http://groups.google.com/group/rubyonrails-core.
> For more options, visit https://groups.google.com/d/optout.
>
--
You received this message because you are subscribed to the Google Groups "Ruby
on Rails: Core" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to rubyonrails-core+unsubscr...@googlegroups.com.
To post to this group, send email to rubyonrails-core@googlegroups.com.
Visit this group at http://groups.google.com/group/rubyonrails-core.
For more options, visit https://groups.google.com/d/optout.
Re: [Rails-core] update_columns doesn't support an empty hash
This behavior was added at https://github.com/rails/rails/pull/7133.
Also don't assume that `update_attributes` and `update_columns` are
analogues. The later is dealing directly with the database without any kind
of interaction with the object instance, so they will behaves differently
in a lot of ways, like type casting for instance.
On Thu, May 7, 2015 at 2:52 PM Rafael Mendonça França <
rafaelmfra...@gmail.com> wrote:
> And what happen if users expect N to be between 1 and and we
> silently do nothing when 0 is sent to these methods?
>
> In my opinion if you don't have changes to be made in the database, just
> don't call the method.
>
> On Thu, May 7, 2015 at 2:47 PM Michael Mahemoff
> wrote:
>
>> Bah I mean "N is between 0 and " (rather than 1 and ).
>>
>>
>> On Thursday, 7 May 2015 18:46:51 UTC+1, Michael Mahemoff wrote:
>>>
>>> Basically because http://en.wikipedia.org/wiki/Null_Object_pattern.
>>> It's often the case that systems have to deal with "N" possible changes,
>>> where N is between 0 and 1. e.g. I might have a procedure to gradually
>>> build up a list of things to change, starting with {} and appending to it
>>> if certain conditions are met. It wouldn't be an exceptional situation if
>>> none of those conditions are met.
>>>
>>> On Thursday, 7 May 2015 18:24:50 UTC+1, Rafael Mendonça França wrote:
Are not both cases invalid input? Why should we accept empty hashes?
On Thu, May 7, 2015 at 2:14 PM Michael Mahemoff
wrote:
> The following will return an error:
>
> > Post.first.update_columns({})
> ArgumentError: Empty list of attributes to change
>
> I think that's surprising, because I see update_columns as an analogue
> to update_attributes, just without callbacks happening. An empty hash for
> the latter is fine:
>
> > Post.first.update_attributes({})
> true
>
> So shouldn't update_columns support an empty hash too? In the rare
> cases where callbacks should be avoided and this is needed, it would save
> having to make a special-case check to prevent the error.
>
> --
> You received this message because you are subscribed to the Google
> Groups "Ruby on Rails: Core" group.
> To unsubscribe from this group and stop receiving emails from it, send
> an email to rubyonrails-co...@googlegroups.com.
> To post to this group, send email to rubyonra...@googlegroups.com.
> Visit this group at http://groups.google.com/group/rubyonrails-core.
> For more options, visit https://groups.google.com/d/optout.
>
--
>> You received this message because you are subscribed to the Google Groups
>> "Ruby on Rails: Core" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to rubyonrails-core+unsubscr...@googlegroups.com.
>> To post to this group, send email to rubyonrails-core@googlegroups.com.
>> Visit this group at http://groups.google.com/group/rubyonrails-core.
>> For more options, visit https://groups.google.com/d/optout.
>>
>
--
You received this message because you are subscribed to the Google Groups "Ruby
on Rails: Core" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to rubyonrails-core+unsubscr...@googlegroups.com.
To post to this group, send email to rubyonrails-core@googlegroups.com.
Visit this group at http://groups.google.com/group/rubyonrails-core.
For more options, visit https://groups.google.com/d/optout.
Re: [Rails-core] update_columns doesn't support an empty hash
Yes. It is raised by `update_all(attributes)`. On Thu, May 7, 2015 at 3:19 PM Xavier Noria wrote: > It makes sense to me, you get passed a hash with the attributes to update, > which could be none. > > This is a no-op edge-case similar to append an empty list to a list, etc., > and could have use cases where the hash is built programatically. > > The implementation generally uses iterators, which is the normal way to > support these edge-cases with no explicit handling, maybe the exception is > raised by update_all(attributes) > > > https://github.com/rails/rails/blob/master/activerecord/lib/active_record/persistence.rb#L312 > > ? > > -- > You received this message because you are subscribed to the Google Groups > "Ruby on Rails: Core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to rubyonrails-core+unsubscr...@googlegroups.com. > To post to this group, send email to rubyonrails-core@googlegroups.com. > Visit this group at http://groups.google.com/group/rubyonrails-core. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-core+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-core@googlegroups.com. Visit this group at http://groups.google.com/group/rubyonrails-core. For more options, visit https://groups.google.com/d/optout.
Re: [Rails-core] update_columns doesn't support an empty hash
I think the error makes sense with update_columns and not with update_attributes. Since the former is essentially a pass through to the database, and the database would raise an error without any columns to update, I'd expect an error when the method is used that way as well. On Thursday, May 7, 2015, Rafael Mendonça França wrote: > Yes. It is raised by `update_all(attributes)`. > > On Thu, May 7, 2015 at 3:19 PM Xavier Noria > wrote: > >> It makes sense to me, you get passed a hash with the attributes to >> update, which could be none. >> >> This is a no-op edge-case similar to append an empty list to a list, >> etc., and could have use cases where the hash is built programatically. >> >> The implementation generally uses iterators, which is the normal way to >> support these edge-cases with no explicit handling, maybe the exception is >> raised by update_all(attributes) >> >> >> https://github.com/rails/rails/blob/master/activerecord/lib/active_record/persistence.rb#L312 >> >> ? >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Ruby on Rails: Core" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to rubyonrails-core+unsubscr...@googlegroups.com >> >> . >> To post to this group, send email to rubyonrails-core@googlegroups.com >> . >> Visit this group at http://groups.google.com/group/rubyonrails-core. >> For more options, visit https://groups.google.com/d/optout. >> > -- > You received this message because you are subscribed to the Google Groups > "Ruby on Rails: Core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to rubyonrails-core+unsubscr...@googlegroups.com > > . > To post to this group, send email to rubyonrails-core@googlegroups.com > . > Visit this group at http://groups.google.com/group/rubyonrails-core. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To unsubscribe from this group and stop receiving emails from it, send an email to rubyonrails-core+unsubscr...@googlegroups.com. To post to this group, send email to rubyonrails-core@googlegroups.com. Visit this group at http://groups.google.com/group/rubyonrails-core. For more options, visit https://groups.google.com/d/optout.
