# Reference Through records in a has many through join

**URL:** <https://www.ruby-forum.com/t/reference-through-records-in-a-has-many-through-join/145059>\
**Category:** Rails\
**Created:** [August 5, 2008, 5:43pm UTC](https://www.ruby-forum.com/t/reference-through-records-in-a-has-many-through-join/145059 "2008-08-05T17:43:26Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![mikej](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a9a28c/32.png) [@mikej](https://www.ruby-forum.com/u/mikej)\
**Post date:** [August 5, 2008, 5:43pm UTC](https://www.ruby-forum.com/t/reference-through-records-in-a-has-many-through-join/145059/1 "2008-08-05T17:43:26Z")

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I have 2 tables (toms and dicks) joined with has\_many through a third  
table (harries).

@tom = Tom.find(1)

How do you reference all the related records in harries. If I do:

@tom.dicks[1].harries

I get records for all records in tom, not just for @tom i.e. with an  
id of 1.

Many thanks,

Mike

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<div class="post-metadata">

**Author:** ![mikej](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a9a28c/32.png) [@mikej](https://www.ruby-forum.com/u/mikej)\
**Post date:** [August 5, 2008, 5:59pm UTC](https://www.ruby-forum.com/t/reference-through-records-in-a-has-many-through-join/145059/2 "2008-08-05T17:59:18Z")

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Thanks very much for the thorough response. It surprises me that  
having declared:

@tom= Tom.find(1)

there is not a more direct route to accessing related harries.

Heh ho,

more thanks,

Mike

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<div class="post-metadata">

**Author:** ![mikej](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a9a28c/32.png) [@mikej](https://www.ruby-forum.com/u/mikej)\
**Post date:** [August 6, 2008, 1:49pm UTC](https://www.ruby-forum.com/t/reference-through-records-in-a-has-many-through-join/145059/3 "2008-08-06T13:49:13Z")

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Having declared @tom= Tom.find(1), you can access @tom.harries which  
is an array of Harry object where tom\_id = 1.  
I though you want to access directly to the related dicks of @tom.

## Sorry for misundertanding

Mathieu BODIN

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<div class="post-metadata">

**Author:** ![mikej](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a9a28c/32.png) [@mikej](https://www.ruby-forum.com/u/mikej)\
**Post date:** [August 5, 2008, 5:51pm UTC](https://www.ruby-forum.com/t/reference-through-records-in-a-has-many-through-join/145059/4 "2008-08-05T17:51:03Z")

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It depends on what you configured as relations between those objects :  
I guess you might have something like that :  
class Tom \< …(whatever ActiveRecord)  
:has\_many :harries  
:has\_many :dicks, :througt =\> :harries  
end

class Dick\< …(whatever ActiveRecord)  
:has\_many :harries  
:has\_many :toms, :througt =\> :harries  
end

class Harry \< …(whatever ActiveRecord)  
:belongs\_to :tom  
:belongs\_to :dick  
end

(I’m not really sure of the correctness of what is written but it’s  
not the point)

Let’s assume that migrations are ok  
So what’s up @tom, let’s say @tom is defined as you proposed  
@tom= Tom.find(1)

now you can access the dicks of @tom (haha!!) like this  
@tom.dicks

so if you want a specified one, you can do something like that

@tom.dicks[42] # it will return the 42 Dick instance of the Array  
represented in @tom.dicks

As this one is an Dick instance, you still have access to his harries,  
like this  
@tom.dicks[42].harries

And if you want a specific Harry instance, you may try something like  
the following  
Harry.find(:first, :conditions =\> [ "tom\_id = ? AND dick\_id = ? ", 1,  
@tom.dicks[42].id])

## Hope it helps

Mathieu BODIN