What is the proper way to execute a SQL statement via DataMapper?

[Johannes Held]

Hello list,

I’m wondering what's the proper way to execute a SQL statement via DataMapper.

Assume I these models are created at runtime:

class Bar
  include DataMapper::Resource
  property :id, :Serial
end

class Foo
  include DataMapper::Resource
  property :a, :Serial
  property :b, :Serial
  belongs_to Bar, :key => true
end

Now I want to create a view (and a model to mirror that view):
create view foo_count as
select a, b, count(bar) as count
from foo
group by a, b

How can I use DataMapper to execute this statement?
Is there a way to use the name system of DataMapper?

--
Cheers, Johannes

[Ted Han]

Check out https://rubygems.org/gems/dm-ar-finders there's a find_by_sql method in there: http://rubydoc.info/gems/dm-ar-finders/1.2.0/frames

Beyond that you can also fire off queries directly at a repository's adapter as well:

1.9.3p194 :004 > DataMapper.repository.adapter.select('select * from candidates limit 1')

 => [#<struct id=1, name="Peter Kinder", slug="peter-kinder", incumbent=true, url=nil>] 

But as you can see, that doesn't give you wrapped models and a collection back.  (the find_by_sql method above does)

On Wed, Jul 25, 2012 at 12:22 PM, Mario Camou <mca...@tecnoguru.com> wrote:

I also need to do this, I want to issue a command to MySQL to set the Transaction Isolation level but haven't found out how to send raw SQL statements through DataMapper. Any takers?

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Ted Han

@knowtheory

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[Ted Han]

Check out https://rubygems.org/gems/dm-ar-finders there's a find_by_sql method in there: http://rubydoc.info/gems/dm-ar-finders/1.2.0/frames

Beyond that you can also fire off queries directly at a repository's adapter as well:

1.9.3p194 :004 > DataMapper.repository.adapter.select('select * from candidates limit 1')

 => [#<struct id=1, name="Peter Kinder", slug="peter-kinder", incumbent=true, url=nil>] 

But as you can see, that doesn't give you wrapped models and a collection back.  (the find_by_sql method above does)

On Wed, Jul 25, 2012 at 12:22 PM, Mario Camou <mca...@tecnoguru.com> wrote:

I also need to do this, I want to issue a command to MySQL to set the Transaction Isolation level but haven't found out how to send raw SQL statements through DataMapper. Any takers?

On Thursday, May 3, 2012 8:19:43 AM UTC+2, Johannes Held wrote:

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