Rails - Oct 2005 - find_by_sql question

I assume if you have a Post class, that Post.find_by_sql should return
an array of Post objects.

But, how does what you return from the sql statement affect the results?

For instance, does it matter if you say "select * from posts" versus
"select id from posts" versus something non-sensical such as
"select
updated_at from categories"?

I''ve seen cetain instances where someone returns a db field in the sql
that does not exist in the model. How does that work? What''s the
relationship between the sql executed and the return object(s).

Thanks,

Ryan

You can only access what you retrieve. Given Rails dynamic nature, if 
you do a
model = Model.find_by_sql(''select attr from models where
id=1'')
your model will only contain attr and trying something else will give an 
"undefined method".

You could even do a
model = Model.find_by_sql(''select attr as blah from models where
id=1'')
and do model.blah. Not recommanded though.

Ryan Wood wrote:
>I assume if you have a Post class, that Post.find_by_sql should return
>an array of Post objects.
>
>But, how does what you return from the sql statement affect the results?
>
>For instance, does it matter if you say "select * from posts"
versus
>"select id from posts" versus something non-sensical such as
"select
>updated_at from categories"?
>
>I''ve seen cetain instances where someone returns a db field in the
sql
>that does not exist in the model. How does that work? What''s the
>relationship between the sql executed and the return object(s).
>
>Thanks,
>
>Ryan
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