gmane.comp.lang.ruby.datamapper

valid? raises error: wrong number of arguments (1 for 0)

Johannes Held — 2012-05-15T12:19:09

I have a model named Fact. A fact belongs to many other models and holds 
some attributes. Think of it as a data-warehouse fact table.

class Fact
  include DataMapper::Resource

  belongs_to :patientposition, :key => true
  belongs_to :controlpointcount, :key => true
  belongs_to :radiationtype, :key => true
  belongs_to :collimatormovement, :key => true
  belongs_to :beamcount, :key => true
  belongs_to :marctype, :key => true

  property :valid, Boolean, :required => true, :default => true
  property :marctestdate_count, Integer, :required => true, :default => 0
  property :realvortest1_count, Integer, :required => true, :default => 0

  timestamps :at
end

All of the other models are described in the same way:
class *Name*
  include DataMapper::Resource
  property :id,  Serial
  property :value, String, :required => true
  validates_uniqueness_of :value
end

If I want to first_or_create a fact issuing e.g.
Fact.first_or_create("patientposition_id"=>2, "controlpointcount_id"=>3, 
"radiationtype_id"=>1, "c

dynamic tables

Clark Snowdall — 2012-05-11T00:59:15

Hello all,

I've dabbled in datamapper in the past, but don't have much experience
in it.  I'm trying to evaluate its usefulness for solving a problem I
have.

I have a number of tables (probably ~50) that I need to get data
from.  Each table has 5 columns in common.  Beyond those 5 columns
each table has various numbers of various other columns; none of them
in common with other tables.

I would like to find a means of ORM that would allow me to declare a
single model that could handle the basic 5 pieces of common data, but
then also access the extra columns dynamically depending on what table
was specified.  I would really prefer NOT to have to write 50 or so
models (especially since this number is being added to and subtracted
from in an ongoing fashion).  I was wondering if perhaps Datamapper
might be able to solve this in a clean dynamic way.

Thoughts anyone?

Thanks,
Snowdall

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

Johannes Held — 2012-05-03T06:19:43

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

Listing all models in a repository (reflection)

jbrennan — 2012-05-02T13:25:14

I'm trying to whip up some debug pages based around all the models in my 
repository and I'm wondering if I can do this dynamically. Is there a way 
to list all the models in a given repository?

I'm not looking to list all the *objects* in the repo (not yet at least), 
but all the different kinds of models and their properties. I poked around 
the docs a little bit but was unable to find what I was looking for.

Any way to do this?

Thanks.

Mutex already locked error in pooling.rb (jruby/torquebox)

Patrik Sundberg — 2012-04-27T15:44:36

Hi,

I'm getting the following error at "random" times in an app I have deployed 
using jruby (1.6.7) on torquebox (2.0.1), using latest datamapper gems: 
https://gist.github.com/2507835

It's not something I can reproduce at will, seems to happen every few days 
under low load.

Anyone has an idea what's going on here? Bug in the pooling code?

Guessing jruby+TB may unearth some bugs under truly parallel threads not 
often encountered by most setups.

Thanks,
Patrik

DataObjects::Postgres::Result

Neil C — 2012-04-22T23:26:57

I executed a pure SQL query against Postgres using DataMapper and got an 
object of class DataObjects::Postgres::Result. However, I can't find any 
kind of documentation indicating how to manipulate this instance to get the 
data. Can you point me to that documentation?

Thanks.

Attributes on an Association

Neil Chaudhuri — 2012-04-21T05:30:57

I need to store people, albums, photos, and the order that photos
appear in an album, so I decided to try adding a "position" attribute
to the association between Photo and Album. Consider the following
models:

class Person
  include DataMapper::Resource
...
end

class Album
  include DataMapper::Resource
...
  has n, :photos, "Photo", :through => :album_photos, :via => :photo
end

class Photo
  include DataMapper::Resource
...

  belongs_to :person, :required => true
  has n, :albums, "Album", :through => :album_photos, :via => :album
end

class AlbumPhoto
  include DataMapper::Resource

  property :position, Integer, :default => 1

  belongs_to :album, :key => true
  belongs_to :photo, :key => true

end

First, is such the right way to achieve this sort of thing? I didn't
see anything like this in the documentation.

To add a wrinkle, I have a model called Book which has a 1:M
relationship with Album. When I execute the following code

    album.album_photos.destroy
    album.album_photos << AlbumPhoto.ne

Query Order

Fred — 2012-04-18T21:18:47

Guys,
how can I set the query (all, first, etc) order to something like
"ifnull(column1, column2) asc", I just can "order =>
[:column1.asc, :column2.asc]", but it does't work for null columns.
Thanks

Many to one association question

Jacob Basham — 2012-04-13T17:18:10

Howdy!

I have a very simple Many to One relationship

class InterviewGroup
  include DataMapper::Resource

  property :id, Serial
  has n, :interviews
end

class Interview
  include DataMapper::Resource

  property :id, Serial
  belongs_to :interview_group
  belongs_to :person
end

The problem is when I destroy an Interview, it deletes the parent 
InterviewGroup. Originally we had a :constraint => :destroy on 
InterviewGroup#interviews, removing the constraint still results in the 
InterviewGroup being destroyed. The odd thing is the related Person is not 
destroyed.

How would I go about fixing this so deleting an Interview will not destroy 
the Group?

Thanks!

decimal field using sqlite

Arthur MM — 2012-04-09T18:26:25

hi, I am having some problem here with field Decimal

My Class:

require 'dm-core'

class Registry
  include DataMapper::Resource

  property :num, Decimal, :key => true,  :precision => 20, :scale => 0
end

require 'dm-migrations'
DataMapper.finalize
DataMapper.setup(:default, 'sqlite::memory:')
DataMapper.auto_migrate!

My Test:

// I start irb
$ irb -r ./dm
/home/arthur/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/yaml.rb:56:in
`<top (required)>':
It seems your ruby installation is missing psych (for YAML output).
To eliminate this warning, please install libyaml and reinstall your
ruby.

// and create a new registry
ruby-1.9.3-p0 :001 > r = Registry.new(:num => 321512420108210029)
 => #<Registry < at >num=#<BigDecimal:9771c54,'0.3215124201 08210029E18',
18(27)>>  // bigdecimal is showing correct num
ruby-1.9.3-p0 :002 > r.save
 => true
ruby-1.9.3-p0 :003 > Registry.all
 => [#<Registry < at >num=#<BigDecimal:98358e8,'0.3215124201 08210048E18',
18(27)>>] // num is wrong
ruby-1.9.3-p0 :004 >
Registry.all.first.num.to_i

Call to DataMapper.auto_upgrade! doesn't return

Nikhil Prabhakar — 2012-04-05T13:15:07

Hi,
 I'm trying to setup a sinatra app on production server. In production 
environment, call to DataMapper.auto_upgrade! does not return. MySQL is 
running on a different server and I can connect to it via mysql command 
line as well as mysql gem. In an irb session I'm doing following steps to 
debug:

require 'rubygems'
require 'data_mapper'
require 'app/models/contact'
require 'environment'
DataMapper.setup(:default, Environment.get_db_conn_hash('production'))
DataMapper.auto_upgrade! # This call doesn't return.

Regards,
nipra

Common Pitfalls Documentation

Dan Kubb (dkubb — 2012-04-02T04:44:34

Hi Everyone,

I just wanted to point the group at a new document on datamapper.org that 
will describe common pitfalls when using DataMapper:

  http://datamapper.org/docs/pitfalls.html

I kicked it off with the most common problem people encounter, with the 
implicit String length. I'll be adding more, but I wanted to get this out 
early for people to comment on.

Feel free to fork the 
repository https://github.com/datamapper/datamapper.github.com and add your 
own as pull requests. The actual source for this page can be found at:

  
https://raw.github.com/datamapper/datamapper.github.com/master/docs/pitfalls.md

repositories

Gabe Anzelini — 2012-03-29T23:25:30

I am need of a setup where I can have on model stored in a pg database
and another is pulled from a legacy system. I need to have
relationships between the two and I really only want to specify which
repository each model is associated with once. Is this possible? And
if so, where can I find the documentation to do it?

Thanks.

getting some dm gems on travis

cldwalker — 2012-03-23T07:54:22

Hi All,
  I've been using dm for more projects and would love to see it on
travis so I know it tests well across rbx, jruby and mri. Would you
all take pull requests to add travis to dm-core, dm-migrations, dm-
timestamps and dm-validations?

Thanks,
Gabriel

P.S. I maintain 20+ gems and can attest to travis being useful for
monitoring support across rubies

Does datamapper model association work with Enumerators ?

stcatz — 2012-03-22T05:16:07

Hi,

Suppose I have a one to many association between Author and Post.

When I am trying to find out all posts authors with each enumberators,
I got errors.

  < at >posts = Post.all

  < at >posts.each do |b|
     p b.author
  end

  errors:
  Rake::ConfigurationError: Please specify the repository path via
the :repository variable
from /home/stcatz/.rvm/gems/ruby-1.9.3-p0/gems/rake-remote_task-2.0.6/
lib/rake/remote_task.rb:311:in `block in mandatory'
from /home/stcatz/.rvm/gems/ruby-1.9.3-p0/gems/rake-remote_task-2.0.6/
lib/rake/remote_task.rb:268:in `call'
from /home/stcatz/.rvm/gems/ruby-1.9.3-p0/gems/rake-remote_task-2.0.6/
lib/rake/remote_task.rb:268:in `block in fetch'
from /home/stcatz/.rvm/gems/ruby-1.9.3-p0/gems/rake-remote_task-2.0.6/
lib/rake/remote_task.rb:321:in `block in protect_env'
        .....

But if I find it directly, it is ok.

  < at >post = Post.first
  p < at >post.author

So, why did this error report out ?

Implementing model inheritance - multiple table inheritance possible?

Abe Voelker — 2012-03-19T21:33:46

I have some questions on how to handle some inheritance I will need to do
in a Rails app.  I am implementing a process where users will be filling
out multi-step forms - a.k.a. wizards - and need to handle several
different types of wizard processes, with new ones cropping up each year
and the old ones staying archived (in other words, there will be lots of
wizard 'types' or flavors in existence).

From a pure OO perspective, these wizards all share some common
functionality, particularly a 'state' attribute which all wizards have to
determine the current step that the user is on, and if they are finished or
not.  This state is managed internally within each different wizard type,
controlled by a state machine which could work very differently between
wizard types, however they all share the same 'completed' state at the end
as a bare minimum.

The basic class diagram I have in my head is of a base Wizard class at the
top, with the basic shared 'state' attribute and some common methods there
and the differen

Optimizing Many-to-Many Query

Neil Chaudhuri — 2012-03-18T19:55:15

I have the following models:

Person
has n, :photos

Album
has n, :photos, :through => Resource
has n, :people, :through => :photos, :via => :person

Photo
belongs_to :person, :required => true
has n, :albums, :through => Resource


So here is what I want:

Given an album, I would like all the photos in that album grouped by
the person they belong to. Ideally, I would love to be able to query
an album for all the people in it, and that collection of people would
have ONLY those photos of theirs in the album. After all, the person
probably has a ton of other photos in other albums that are
irrelevant.

I have tried a ton of queries. Some are just syntactically off; others
are not quite right and way too slow anyway. Any insight into a proper
query or in reorganizing my model is really appreciated.

Thanks.

Modeling Multiple Many-to-Many Relationships With One Model In Common

Neil Chaudhuri — 2012-03-15T05:12:32

I have a fairly straightforward modeling task involving People,
Albums, and Photos. Here are the business rules:

*One person can have many photos.
*One album can have many photos.
*One album can have photos of many people.
*An album can have multiple photos belonging to the same person, but
not necessarily all the photos belonging to that person.
*Given an album, I would like some way to aggregate sets of photos by
the person they belong to (where each set is a subset of all the
photos that person has). So for example, I would like to say that in
Album 10, Bobby has his photos 9, 17, and 41 and Sally has her photos
47, 57, 93, 201, 203. Of course, Bobby and Sally both have a lot more
photos than that but just not in this album.

I would think the tables would look like this:

Person
id | name

Album
id | name

Photo
id | filename

PersonAlbumPhoto
person_id | album_id | photo_id

My questions are these:

*Is this a reasonable model for the business rules as I described? I
am happy to hear of something more

DataMapper 1.2.0 not returning error messages

Paul — 2012-03-07T17:56:40

Hi,

I recently upgraded to DataMapper 1.2.0 from 1.1.0 and I am not
getting validation error messages anymore.  I still get
DataMapper::Validations::ValidationErrors in my exception but no error
messages are populated.

Any ideas as to why this happens?

Thanks,

Paul

contribute to DM 2.x

Christiaan Van den Poel — 2012-03-01T16:06:32

I would like to contribute to the DM 2.x (if possible)

Where can I find more info the current development?

TIA

Christiaan

What data Type should I use to store images?

manu — 2012-02-29T20:44:13

Hello

If I want to manipulate small images in my model (e.g. icons), what
Type should I use in my model? Binary?

e.g. property :image,   Binary

I'm using a postgresql database.

Many thanks