Rails - Apr 2006 - preloading child rows just a level deeper...

hiho.

following problem.
i have 3 tables in my database with each representing an object.
lets say
A belongs_to B belongs_to C.

when i do
my_a = A.find(:all)
i can access B as my_a.b and C as my_a.b.c
thats fine but rails querys the database each time i do that

so is use
my_a = A.find(:all, :include => :b)
works fine for my_a.b but not for my_a.b.c

so i tried
my_a = A.find(:all, :include => [:b, :c])
but that gives an error:
"Association named ''c'' was not found; perhaps you
misspelled it?"

well, no i didnt misspelled, but table A dont has an c_id. only table B 
knows to what c it belongs
no wonder there is an error ... :/

question is:
Can i preload the rows of C like i do it with the rows in B when i query 
table A?

i hope i made it clear enough... :/

[ No, i cant/dont want to use STI ]

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Gerald,

Try googling for ''rails bottomless eager loading''--new feature
in 1.1,
I believe.


--

Ed Frederick - edwardfrederick.com

On 4/10/06, Gerald Schenke <realazrael@gmx.de>
wrote:
> hiho.
>
> following problem.
> i have 3 tables in my database with each representing an object.
> lets say
> A belongs_to B belongs_to C.
>
> when i do
> my_a = A.find(:all)
> i can access B as my_a.b and C as my_a.b.c
> thats fine but rails querys the database each time i do that
>
> so is use
> my_a = A.find(:all, :include => :b)
> works fine for my_a.b but not for my_a.b.c
>
> so i tried
> my_a = A.find(:all, :include => [:b, :c])
> but that gives an error:
> "Association named ''c'' was not found; perhaps you
misspelled it?"
>
> well, no i didnt misspelled, but table A dont has an c_id. only table B
> knows to what c it belongs
> no wonder there is an error ... :/
>
> question is:
> Can i preload the rows of C like i do it with the rows in B when i query
> table A?
>
> i hope i made it clear enough... :/
>
> [ No, i cant/dont want to use STI ]
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

To follow up my previous reply:

try: A.find(:all, :include => { :b => { :c })


On 4/10/06, Gerald Schenke <realazrael@gmx.de>
wrote:
> hiho.
>
> following problem.
> i have 3 tables in my database with each representing an object.
> lets say
> A belongs_to B belongs_to C.
>
> when i do
> my_a = A.find(:all)
> i can access B as my_a.b and C as my_a.b.c
> thats fine but rails querys the database each time i do that
>
> so is use
> my_a = A.find(:all, :include => :b)
> works fine for my_a.b but not for my_a.b.c
>
> so i tried
> my_a = A.find(:all, :include => [:b, :c])
> but that gives an error:
> "Association named ''c'' was not found; perhaps you
misspelled it?"
>
> well, no i didnt misspelled, but table A dont has an c_id. only table B
> knows to what c it belongs
> no wonder there is an error ... :/
>
> question is:
> Can i preload the rows of C like i do it with the rows in B when i query
> table A?
>
> i hope i made it clear enough... :/
>
> [ No, i cant/dont want to use STI ]
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

thank you so much!
awesome!!!

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