# Drop down boxes from table data

**URL:** <https://www.ruby-forum.com/t/drop-down-boxes-from-table-data/192590>\
**Category:** Rails\
**Created:** [August 2, 2010, 6:28pm UTC](https://www.ruby-forum.com/t/drop-down-boxes-from-table-data/192590 "2010-08-02T18:28:19Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![disruptive](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/49beb7/32.png) [@disruptive](https://www.ruby-forum.com/u/disruptive)\
**Post date:** [August 2, 2010, 6:28pm UTC](https://www.ruby-forum.com/t/drop-down-boxes-from-table-data/192590/1 "2010-08-02T18:28:19Z")

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Hi

I have another question for how best to do this. Now I have been  
following the tutorial at:  
[http://www.tunaslut.com/learning-ruby-drop-down-lists-in-one-to-many-relationships](http://www.tunaslut.com/learning-ruby-drop-down-lists-in-one-to-many-relationships),  
however when I change the view over from

\<% @cities.each do |city| %\>

 \<%=h city.city\_name %\> \<%=h city.country\_id %\>

to:

\<% @cities.each do |city| %\>

 \<%=h city.city\_name %\> \<%=h city.country.country\_name %\>

The system breaks with the following error

NoMethodError in Cities#index

Showing app/views/cities/index.html.erb where line #12 raised:

undefined method `country\_name’ for nil:NilClass  
Extracted source (around line #12):

when attempting to display data on cities

My questions are:

1. Is there an easier way of doing drop down boxed populated from a  
table?
2. is this foreign key assignment working?
3. is this a good way of doing FK asignments? is there a better way.

Please forgive me, I’m old school, more used to the SQL statements…

Thanks again.

---

<div class="post-metadata">

**Author:** ![disruptive](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/49beb7/32.png) [@disruptive](https://www.ruby-forum.com/u/disruptive)\
**Post date:** [August 2, 2010, 7:22pm UTC](https://www.ruby-forum.com/t/drop-down-boxes-from-table-data/192590/2 "2010-08-02T19:22:50Z")

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disruptive tech wrote:

> Hi
> 
> I have another question for how best to do this. Now I have been  
> following the tutorial at:  
> [http://www.tunaslut.com/learning-ruby-drop-down-lists-in-one-to-many-relationships](http://www.tunaslut.com/learning-ruby-drop-down-lists-in-one-to-many-relationships),  
> however when I change the view over from
> 
> \<% @cities.each do |city| %\>
> 
> \<%=h city.city\_name %\> \<%=h city.country\_id %\>
> 
> to:
> 
> \<% @cities.each do |city| %\>
> 
> \<%=h city.city\_name %\> \<%=h city.country.country\_name %\>
> 
> The system breaks with the following error
> 
> NoMethodError in Cities#index
> 
> Showing app/views/cities/index.html.erb where line #12 raised:
> 
> undefined method `country\_name’ for nil:NilClass

…which means that city.country is nil. You have to make it not be.

> Extracted source (around line #12):
> 
> when attempting to display data on cities
> 
> My questions are:
> 
> 1. Is there an easier way of doing drop down boxed populated from a  
> table?

collection\_select

> 1. is this foreign key assignment working?
> 2. is this a good way of doing FK asignments? is there a better way.

I don’t see any assignment in your code.

> Please forgive me, I’m old school, more used to the SQL statements…

What’s that got to do with anything?

> Thanks again.

## Best,

Marnen Laibow-Koser  
[http://www.marnen.org](http://www.marnen.org)  
removed\_email\_address@domain.invalid