# Acts\_as\_list index has to be :position?

**URL:** <https://www.ruby-forum.com/t/acts-as-list-index-has-to-be-position/125106>\
**Category:** Rails\
**Created:** [January 5, 2008, 3:07pm UTC](https://www.ruby-forum.com/t/acts-as-list-index-has-to-be-position/125106 "2008-01-05T15:07:43Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![taro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/df705f/32.png) [@taro](https://www.ruby-forum.com/u/taro)\
**Post date:** [January 5, 2008, 3:07pm UTC](https://www.ruby-forum.com/t/acts-as-list-index-has-to-be-position/125106/1 "2008-01-05T15:07:43Z")

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## I’m using MessageBoard (child) to acts\_as\_list for Forum (parent). The models looks as such:

## class Forum \< ActiveRecord::Base #This is a superset of message boards has\_many :message\_boards, :order =\> :order, :dependent =\> :destroy … end

class MessageBoard \< ActiveRecord::Base  
#This is a subset of forums  
belongs\_to :forum

## #This causes MessageBoard to act as a list #it uses order as its index acts\_as\_list :scope =\> :forum\_id … end

## A slight mistake on my part, I wanted the message boards to be ordered by the MySQL (I use Rails 1.2.5) column :order (as seen in line :order =\> :order). However, this error arises:

Loaded suite message\_board\_test  
Started  
…E.  
Finished in 0.347567 seconds.

1. Error:  
test\_title\_overlap(MessageBoardTest):  
ActiveRecord::StatementInvalid: Mysql::Error: #42S22Unknown column  
‘position’ in ‘order clause’: SELECT \* FROM message\_boards WHERE  
(forum\_id = 2) ORDER BY position DESC LIMIT 1  
…

* * *

Does the indexed column name HAVE to be “position”?

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<div class="post-metadata">

**Author:** ![taro](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/df705f/32.png) [@taro](https://www.ruby-forum.com/u/taro)\
**Post date:** [January 9, 2008, 8:52pm UTC](https://www.ruby-forum.com/t/acts-as-list-index-has-to-be-position/125106/2 "2008-01-09T20:52:58Z")

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You can specify a :column attribute. See  
[http://ar.rubyonrails.com/classes/ActiveRecord/Acts/List/ClassMethods.html](http://ar.rubyonrails.com/classes/ActiveRecord/Acts/List/ClassMethods.html)