# Creating a selection box

**URL:** <https://www.ruby-forum.com/t/creating-a-selection-box/146529>\
**Category:** Rails\
**Created:** [August 22, 2008, 1:51am UTC](https://www.ruby-forum.com/t/creating-a-selection-box/146529 "2008-08-22T01:51:26Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![nodrew](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/4491bb/32.png) [@nodrew](https://www.ruby-forum.com/u/nodrew)\
**Post date:** [August 22, 2008, 1:51am UTC](https://www.ruby-forum.com/t/creating-a-selection-box/146529/1 "2008-08-22T01:51:26Z")

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I want to display a selection box on a webpage using data from my DB.  
The data is an array @schools returned by the find method of  
ActiveRecord. I tried the following:

\<% school = {:id =\> @student\_data.school\_id}%\>  
\<%=collection\_select :school, :id, @schools, :id, :name%\>

I get the error:

undefined method `map’ for #School:0x8680ae4

Any ideas what my problem could be?

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**Author:** ![nodrew](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/4491bb/32.png) [@nodrew](https://www.ruby-forum.com/u/nodrew)\
**Post date:** [August 22, 2008, 2:05am UTC](https://www.ruby-forum.com/t/creating-a-selection-box/146529/2 "2008-08-22T02:05:33Z")

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On 22 Aug 2008, at 00:51, Drew B. wrote:

> I want to display a selection box on a webpage using data from my DB.  
> The data is an array @schools returned by the find method of  
> ActiveRecord. I tried the following:
> 
> \<% school = {:id =\> @student\_data.school\_id}%\>  
> \<%=collection\_select :school, :id, @schools, :id, :name%\>

> I get the error:
> 
> undefined method `map’ for #School:0x8680ae4

Sounds like @schools is a single record not an array.

Fred

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**Author:** ![nodrew](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/4491bb/32.png) [@nodrew](https://www.ruby-forum.com/u/nodrew)\
**Post date:** [August 22, 2008, 4:48pm UTC](https://www.ruby-forum.com/t/creating-a-selection-box/146529/3 "2008-08-22T16:48:38Z")

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You were right. I accidentally did a find\_by instead of find\_all\_by.

Thanks!