# Named scope returns uninitialized objects

**URL:** <https://www.ruby-forum.com/t/named-scope-returns-uninitialized-objects/187021>\
**Category:** Rails\
**Created:** [April 15, 2010, 10:08pm UTC](https://www.ruby-forum.com/t/named-scope-returns-uninitialized-objects/187021 "2010-04-15T22:08:44Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![mdeering](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/278dde/32.png) [@mdeering](https://www.ruby-forum.com/u/mdeering)\
**Post date:** [April 15, 2010, 10:08pm UTC](https://www.ruby-forum.com/t/named-scope-returns-uninitialized-objects/187021/1 "2010-04-15T22:08:44Z")

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Hello,

An issue with a Rails named scope has been stumping me for quite  
sometime, and I’m hoping someone can point out the flaw. I have a model,  
Machine, with the following named scope:

named\_scope :needs\_updates, lambda {  
{ :select =\> self.column\_names.collect{|c|  
%Q/“machines”."#{c}"/}.join(’,’),  
:group =\> self.column\_names.collect{|c|  
%Q/“machines”."#{c}"/}.join(’,’),  
:joins =\> ‘LEFT JOIN “machine\_updates” ON  
“machine\_updates”.“machine\_id” = “machines”.“id”’,  
:having =\> [’“machines”.“manual\_updates” = ? AND  
“machines”.“in\_use” = ? AND (MAX(“machine\_updates”.“date”) IS NULL OR  
MAX(“machine\_updates”.“date”) \< ?)’,  
true, true, UPDATE\_THRESHOLD.days.ago]  
}  
}

The named scope works fine in development mode, and with my current  
dataset returns two models as expected. In production mode, however, it  
returns two models, but they are uninitialized; that is, actual objects  
are returned, but all the fields (including id) are nil. When inspecting  
the return value of the named scope in the console, the following is  
returned:

[#, #]

(That is, objects with no values.)

The production and development databases are essentially the same—both  
are using SQLite for DB storage. I’m using Rails 2.3.5 with no plugins.

Any idea what’s wrong?

* * *

Michael D.  
removed\_email\_address@domain.invalid

---

<div class="post-metadata">

**Author:** ![mdeering](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/278dde/32.png) [@mdeering](https://www.ruby-forum.com/u/mdeering)\
**Post date:** [April 15, 2010, 11:51pm UTC](https://www.ruby-forum.com/t/named-scope-returns-uninitialized-objects/187021/2 "2010-04-15T23:51:12Z")

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> Have you tried running the sql this generates by hand and seeing if  
> the result set looks normal ?

Yep. Running the SQL generated by Rails (via script/dbconsole) returns  
the expected result set.

* * *

Michael D.  
removed\_email\_address@domain.invalid

---

<div class="post-metadata">

**Author:** ![mdeering](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/278dde/32.png) [@mdeering](https://www.ruby-forum.com/u/mdeering)\
**Post date:** [April 15, 2010, 10:10pm UTC](https://www.ruby-forum.com/t/named-scope-returns-uninitialized-objects/187021/3 "2010-04-15T22:10:30Z")

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On Apr 15, 6:46 pm, Michael D. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> ```
> }
> 
> ```
> 
> Any idea what’s wrong?  
> Have you tried running the sql this generates by hand and seeing if  
> the result set looks normal ?

Fred