# Find rows with associations in habtm

**URL:** <https://www.ruby-forum.com/t/find-rows-with-associations-in-habtm/59336>\
**Category:** Rails\
**Created:** [May 3, 2006, 6:57pm UTC](https://www.ruby-forum.com/t/find-rows-with-associations-in-habtm/59336 "2006-05-03T18:57:38Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![stepheneb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/71e660/32.png) [@stepheneb](https://www.ruby-forum.com/u/stepheneb)\
**Post date:** [May 3, 2006, 6:57pm UTC](https://www.ruby-forum.com/t/find-rows-with-associations-in-habtm/59336/1 "2006-05-03T18:57:38Z")

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This may have been asked/answered before - if so, i apologise…

I have the following table layout in a habtm relationship:

* * *

| products | ----| categories\_products |-----| categories |

* * *

What would be the best way to pull out all the products for a given  
category? At the moment, i’ve got it going by specifing a join manually  
in the find() but that just doesn’t seem groovey enough for Rails :0)

Cheers,

Steve

---

<div class="post-metadata">

**Author:** ![stepheneb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/71e660/32.png) [@stepheneb](https://www.ruby-forum.com/u/stepheneb)\
**Post date:** [May 3, 2006, 6:57pm UTC](https://www.ruby-forum.com/t/find-rows-with-associations-in-habtm/59336/2 "2006-05-03T18:57:51Z")

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On May 1, 2006, at 11:26 AM, Stephen B. wrote:

> This may have been asked/answered before - if so, i apologise…

FYI, this is just about as Rails 101 as you can get…

> I have the following table layout in a habtm relationship:
> 
> * * *
> 
> | products | ----| categories\_products |-----| categories |
> 
> * * *
> 
> What would be the best way to pull out all the products for a given  
> category? At the moment, i’ve got it going by specifing a join  
> manually in the find() but that just doesn’t seem groovey enough  
> for Rails :0)

Assuming that you have:

has\_and\_belongs\_to\_many: products

In your Category model class definition, you can simply do:

@category = Category.find(1)  
@products = @category.products

That will give you an array of Product items, all of them associated  
with that particular Category. This, and a whole lot more is  
explained in the API docs: [rails.rubyonrails.org](http://rails.rubyonrails.org). Find the link on  
the left for ActiveRecord::Associations.

-Brian

---

<div class="post-metadata">

**Author:** ![stepheneb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/71e660/32.png) [@stepheneb](https://www.ruby-forum.com/u/stepheneb)\
**Post date:** [May 3, 2006, 6:57pm UTC](https://www.ruby-forum.com/t/find-rows-with-associations-in-habtm/59336/3 "2006-05-03T18:57:53Z")

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That’s great thanks. I actually oversimplified my example as my  
products actually have a habtm relationship with 2 tables: products -\>  
activities and destinations. I’ve used a join to search the 2 joiner  
tables - works well!

Steve

---

<div class="post-metadata">

**Author:** ![stepheneb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/71e660/32.png) [@stepheneb](https://www.ruby-forum.com/u/stepheneb)\
**Post date:** [May 3, 2006, 6:58pm UTC](https://www.ruby-forum.com/t/find-rows-with-associations-in-habtm/59336/4 "2006-05-03T18:58:10Z")

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Point taken - consider my wrist well and truly slapped :0)

Steve

---

<div class="post-metadata">

**Author:** ![stepheneb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/71e660/32.png) [@stepheneb](https://www.ruby-forum.com/u/stepheneb)\
**Post date:** [May 3, 2006, 6:58pm UTC](https://www.ruby-forum.com/t/find-rows-with-associations-in-habtm/59336/5 "2006-05-03T18:58:03Z")

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On May 1, 2006, at 12:58 PM, Stephen B. wrote:

> That’s great thanks. I actually oversimplified my example as my  
> products actually have a habtm relationship with 2 tables: products  
> → activities and destinations. I’ve used a join to search the 2  
> joiner tables - works well!

Another quick FYI (not just for Steve, this is merely a convenient  
example), if you want to get appropriate help/advice, please take the  
time to explain the whole problem. The more information and context,  
the easier it will be for the community to help you.

I know I shouldn’t have to say it, but, please don’t be a Help  
Vampire: [http://www.slash7.com/pages/vampires](http://www.slash7.com/pages/vampires)

Work well with the community, so that the community can work well  
with you.

-Brian