# Trouble getting select to work

**URL:** <https://www.ruby-forum.com/t/trouble-getting-select-to-work/97580>\
**Category:** Rails\
**Created:** [July 8, 2006, 3:34am UTC](https://www.ruby-forum.com/t/trouble-getting-select-to-work/97580 "2006-07-08T03:34:54Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![daborg69](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/d9b06d/32.png) [@daborg69](https://www.ruby-forum.com/u/daborg69)\
**Post date:** [July 8, 2006, 3:34am UTC](https://www.ruby-forum.com/t/trouble-getting-select-to-work/97580/1 "2006-07-08T03:34:54Z")

</div>

I’ve tried pulling this together from examples in the book, searching  
the web and this list, but so far I’ve not been able to get it working  
just right.

My table is a categories table with id and category fields.

My form has the following:

\<%= select('category', 'category', @categories = Category.find(:all, :order =\> "category").map {|cat| [cat.category, cat.category]}) %\>

I used [[cat.category, cat.category] as I am not interested in the id  
and want both values to be equal to the category itself.

This form is a Donation form. One of the fields in the donation record  
is a category. The database does not relate these two tables. What I  
want to do is simply populate the dropdown category box from the  
categories table and allow a category to be selected and that category  
be populated to the donation record.

In other words:

1. Pull all categories into the form from the categories table into a  
dropdown box on adding the record
2. Upon editing the record, again pull the categories as in step one,  
but this time cause the category selected when the record was added to  
be selected in the dropdown box, otherwise upon update the wrong  
category would be updated to the record.

The dropdown box is populated with the categories; however, when the  
record is added to the database, the category field is not populated.

The log file shows the following:

e[4;35;1mCategory Load (0.078000)e[0m e[0mSELECT \* FROM categories  
ORDER BY category e[0m

So far so good.

And then on adding the record:

Parameters: {“commit”=\>“Create”, “category”=\>{“category”=\>“Furniture -  
Kitchen”}, “action”=\>“create”,  
e[4;35;1mSQL (0.062000)e[0m e[0mINSERT INTO donations  
(`best_contact_time`, `city`, `created_on`,  
`item_desc`, `category`, …

The category of “Furniture - Kitchen” is probably the eighth in the list  
and is in fact the one chosen.

Two things then:

1. Why isn’t this being updated into the database record (the field in  
the donation record is named category)

2. Will the current code be sufficent to cause the category in the  
record to be selected upon editing of the record? Since the code in the  
form populates the dropdown box, might I need to then after that  
immediately cause the category from the record to be the selected value  
with following additonal code?

I suspect that there is no actual “selection” happening and if there  
were, the donation’s record field would be populated and that would also  
solve the issue when updating as well, and yet the create statement in  
the log file appears to be showing a value!

Thanks for any help on this. I’ve found the dropdown boxes to be  
particularly troubling.

---

<div class="post-metadata">

**Author:** ![daborg69](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/d9b06d/32.png) [@daborg69](https://www.ruby-forum.com/u/daborg69)\
**Post date:** [July 9, 2006, 11:20am UTC](https://www.ruby-forum.com/t/trouble-getting-select-to-work/97580/2 "2006-07-09T11:20:55Z")

</div>

Prob worth posting you model definitions but I’ve made some assumptions  
about your likely models with some suggestions below:

Scott H. wrote:

> I used [[cat.category, cat.category] as I am not interested in the id  
> and want both values to be equal to the category itself.

You may not be interested in the id, but rails will be (assuming you  
have a has\_many/belongs\_to relationship between Category and Donation)  
as this is what it will use in the category\_id field in the donations  
table. Assuming this is part of a Donation form you will prob benefit  
from changing the select to select(‘donation’, ‘category\_id’,  
@categories …), depending on your models and how your controller  
action will assign the category (automatically, through  
Donation.new(params[:donation]), or through specific assignment  
@donation = Donation.new; @donation.category =  
Category.find(params[:category]); #etc

---

<div class="post-metadata">

**Author:** ![daborg69](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/d9b06d/32.png) [@daborg69](https://www.ruby-forum.com/u/daborg69)\
**Post date:** [July 9, 2006, 3:48pm UTC](https://www.ruby-forum.com/t/trouble-getting-select-to-work/97580/3 "2006-07-09T15:48:16Z")

</div>

Chris T wrote:

> Prob worth posting you model definitions but I’ve made some assumptions  
> about your likely models with some suggestions below:
> 
> Scott H. wrote:
> 
> > I used [[cat.category, cat.category] as I am not interested in the id  
> > and want both values to be equal to the category itself.
> 
> You may not be interested in the id, but rails will be (assuming you  
> have a has\_many/belongs\_to relationship between Category and Donation)  
> as this is what it will use in the category\_id field in the donations  
> table. Assuming this is part of a Donation form you will prob benefit  
> from changing the select to select(‘donation’, ‘category\_id’,  
> @categories …), depending on your models and how your controller  
> action will assign the category (automatically, through  
> Donation.new(params[:donation]), or through specific assignment  
> @donation = Donation.new; @donation.category =  
> Category.find(params[:category]); #etc

Thank you for the response Chris. It is much appreciated. I apologize  
for the confusion resulting from my lack of clarity and insufficient  
information surrounding the problem.

Two tables are involved here. The first is the categories table with the  
following definition:

id  
category

The second table is donations with the following defintion (partial):

id  
item  
item\_desc  
category (actual category and not category\_id)  
…

There is no relationship of 1:m or of any kind in the database or Rails.  
Why? Design choice really. Only one way for categories to get into the  
database: through the categories maintenance forms. The dropdown box on  
the donations forms, create and update provide the only means of  
category populating the donations record, and since the dropdown box on  
the donations form is populated directly from the categories table,  
well, the data must certainly be valid.

The scenario is that upon creating or updating a donations record, the  
dropdown box is populated with categories from the categories table.

A number of things have to happen here.

1. By default the first category retrieved from the categories table  
will be showing in the dropdown box. If say the third category is  
selected, that category of course needs to be populated in the donations  
record.

2. When updating the donations record, again the categories are  
retrieved from the categories table, but the default category, the first  
retrieved from the categories table, must not be showing in the dropdown  
box, but instead the one in the existing donations record must be  
showing; in this scenario it would be the third category in the list.

3. If the category is not changed, the one showing, again in this  
scenario the third one, must still be the one to populate the donations  
record upon update. And of course if the category is changed, the one  
then showing would update into the donations record.

I ran into this very same problem when doing this app using JSPs,  
Hibernate and Tiles. I’d scoured the books, the internet, reading  
articles and so forth for just the perfect example of how to do this. I  
just could not find one that suited this same scenario, which I found  
odd.

Hopefully my explanation of this problem and the database, form and  
general setup is sufficient so that the resolution makes sense as well.

Of course I played around so much that I can’t even remember now what  
didn’t work exactly!

The book, Agile Web D. with Rails gave me the following code  
example, which provided the basis from which to begin with:

\<%= User.find(:all, :order =\> “name”).map {|u| [u.name, u.id]}  
select(:user, :name, @users)  
%\>

What I ended up with, and this works exactly as I had hoped for and  
needed, was:

\<%= select(“donation”, ‘category’, @categories = Category.find(:all,  
:order =\> “category”).map {|cat| [cat.category, cat.category]}) %\>

I didn’t use the id here from the category table records as all I really  
wanted returned from the form was the category value itself which was  
then populated into the donations record and table.

You however Chris did provide me with the clue I needed when you  
mentioned using ‘donation’. Thank you. That led me to what I now have!