rails3 migration to add new column does not save values to table - ruby-on-rails-3

So, I created the following migration:
class AddAclToUsers < ActiveRecord::Migration
def self.up
add_column :users, :acl, :integer
end
def self.down
remove_column :users, :acl
end
end
however, after modifying the various erb files in the view, values entered in edit.html.erb are not saved to the database.
I can manually start SQlite3 and select * the table and see that the column was created but no values are entered. I can also manually UPDATE or INSERT numbers into the new column which the controller queries and displays correctly.
Any suggestions on what may be wrong with the frameworks udate/save??
-daniel

Please check if there is a list of attr_accessible in your User model. If you are using Devise like gem/plugin for authentication you would have a list of attr_accessible in the model.
Add new attribute (acl in your case) to the attr_accessible list.
If this is not the case, I would like you to paste your view, controller and model code

Related

Adding a column Migration with a default value in ruby on rails

I am using SQLite3 and I would like the following to work:
class AddNameToGoal < ActiveRecord::Migration
def change
add_column :goals, :goal_name, :text, default: goal.exercise.name
end
end
Or maybe this makes more sense as what I'm trying to do:
add_column :goals, :gname, :text, default: Goal.find(row_id).exercise.name
How do I get the above to work.
I doubt it will work as it is but that's what I want.
Specifically, The user is associated with an Exercise through the exercise_id column.
belongs_to :user
belongs_to :exercise
has_many :workouts, dependent: :destroy
(This is the model for Goal)...
I would like the user to be able to choose their own name for the Goal but I can give them the hint to name the goal after the Exercise's name and if they choose to leave it blank it will default to the exercise's name. More importantly this must happen on the SQL side so that later when I have a collection drop down which requires a name of the goal they will need a name which corresponds to the exercise.
<%= f.collection_select(:goal_id, #goals, :id,
:goal_name, :include_blank => "Please Select") %>
The Exercise Model is made in Rails to have
id, Name, other columns.
Exercise Model:
class Exercise < ActiveRecord::Base
has_one :goal
Is there a strategy by which that is possible.
Another option would be to help me find a strategy for active record so that I can do:
<%= f.collection_select(:goal_id, #goals, :id,
:goal_name, :include_blank => "Please Select") %>
with (something else to replace goal_name with Exercise.name like goal.exercise.name and goal.id and show only the ID.
Doing this when you define the column on the table is problematic. I definitely think doing it upon creation, in the model, is how you'd want to go.
You might also check out the default_value_for gem and see if it helps.
Hi so in case any body ever wants to do this:
I figured out a strategy...
This is perfect for anything that has an instance of name in terms of the user.
For example, you have something that tracks your Car and you want to give that Car by default the name which comes from that Car's Make_and_Model (model) in Rails.
Naturally when someone says they have a new "Honda Accord" then they get to have that name, but if they ever want to change it to "Lucy" because her name is Lucy and you better treat her with the respect she deserves!, then this gives you the option to do that.
You do not want to change the name for that whole Make&Model you only want to change the name for that specific car.make_and_model which belongs_to User.
If you are wanting something to have a name that defaults to another name but allows the user to change that. Do that on the model level... by setting a before_save method inside the model... like so:
before_save :default_values
def default_values
self.goal_name = self.exercise.name if self.goal_name.nil?
end

RoR: how can I add columns to my database on my live heroku app?

I am trying to add :price, :location, and :product to the columns for my microposts table. I have already done a bunch of other migrations and I have heard that rolling back all of migrations and redoing them is error prone. So I guess the other option is the schema file? I have heard that the schema file is just to be read and not edited. I have been looking at http://guides.rubyonrails.org/migrations.html but can't find the right info. They briefly talk about change_table which I think could be useful but it doesn't go into depth. Is this what I am looking for?
Just create a new standalone migration:
rails g migration add_price_location_and_product_to_microposts
It will create a file in the db/migrate folder, edit it:
def change
add_column :microposts, :price, :float # dont forget to change the type to the columns
add_column :microposts, :location, :string
add_column :microposts, :product, :integer
end
(You can define the change method, instead of up and down because add_column is a reversible command.)
And then, run rake db:migrate

Modeling inheritance with Ruby/Rails ORMs

I'm trying to model this inheritance for a simple blog system
Blog has many Entries, but they may be different in their nature. I don't want to model the Blog table, my concern is about the entries:
simplest entry is an Article that has title and text
Quote, however, does not have a title and has short text
Media has a url and a comment...
etc...
What is a proper way to model this with Ruby on Rails? That is
Should I use ActiverRecord for this or switch to DataMapper?
I would like to avoid the "one big table" approach with lots of empty cells
When I split the data into Entry + PostData, QuoteData etc can I have belongs_to :entry in these Datas without having has_one ??? in the Entry class? That would be standard way to do it in sql and entry.post_data may be resolved by the entry_id in the postdata table.
EDIT: I don't want to model the Blog table, I can do that, my concern is about the entries and how would the inheritance be mapped to the table(s).
I've come across this data problem several times and have tried a few different strategies. I think the one I'm a biggest fan of, is the STI approach as mentioned by cicloon. Make sure you have a type column on your entry table.
class Blog < ActiveRecord::Base
# this is your generic association that would return all types of entries
has_many :entries
# you can also add other associations specific to each type.
# through STI, rails is aware that a media_entry is in fact an Entry
# and will do most of the work for you. These will automatically do what cicloon.
# did manually via his methods.
has_many :articles
has_many :quotes
has_many :media
end
class Entry < ActiveRecord::Base
end
class Article < Entry
has_one :article_data
end
class Quote < Entry
has_one :quote_data
end
class Media < Entry
has_one :media_data
end
class ArticleData < ActiveRecord::Base
belongs_to :article # smart enough to know this is actually an entry
end
class QuoteData < ActiveRecord::Base
belongs_to :quote
end
class MediaData < ActiveRecord::Base
belongs_to :media
end
The thing I like about this approach, is you can keep the generic Entry data in the entry model. Abstract out any of the sub-entry type data into their own data tables, and have a has_one association to them, resulting in no extra columns on your entries table. It also works very well for when you're doing your views:
app/views/articles/_article.html.erb
app/views/quotes/_quote.html.erb
app/views/media/_media.html.erb # may be medium here....
and from your views you can do either:
<%= render #blog.entries %> <!-- this will automatically render the appropriate view partial -->
or have more control:
<%= render #blog.quotes %>
<%= render #blog.articles %>
You can find a pretty generic way of generating forms as well, I usually render the generic entry fields in an entries/_form.html.erb partial. Inside that partial, I also have a
<%= form_for #entry do |f| %>
<%= render :partial => "#{f.object.class.name.tableize}/#{f.object.class.name.underscore}_form", :object => f %>
<% end %>
type render for the sub form data. The sub forms in turn can use accepts_nested_attributes_for + fields_for to get the data passed through properly.
The only pain I have with this approach, is how to handle the controllers and route helpers. Since each entry is of its own type, you'll either have to create custom controllers / routes for each type (you may want this...) or make a generic one. If you take the generic approach, two things to remember.
1) You can't set a :type field through update attributes, your controller will have to instantiate the appropriate Article.new to save it (you may use a factory here).
2) You'll have to use the becomes() method (#article.becomes(Entry)) to work with the entry as an Entry and not a subclass.
Hope this helps.
Warning, I've actually used Media as a model name in the past. In my case it resulted in a table called medias in rails 2.3.x however in rails 3, it wanted my model to be named Medium and my table media. You may have to add a custom Inflection on this naming, though I'm not sure.
You can handle this easily using ActiveRecord STI. It requires you to have a type field in your Entries table. This way you can define your models like this:
def Blog > ActiveRecord::Base
has_many :entries
def articles
entries.where('Type =', 'Article')
end
def quotes
entries.where('Type =', 'Quote')
end
def medias
entries.where('Type =', 'Media')
end
end
def Entry > ActiveRecord::Base
belongs_to :blog
end
def Article > Entry
end
def Quote > Entry
end
def Media > Entry
end

Default value not populating in migration with Rails and Postgresql

I am currently trying to run this migration:
class AddDroppedProjectsCountToUser < ActiveRecord::Migration
def self.up
add_column :users, :dropped_projects, :integer, {:default=>0, :required=>true}
end
def self.down
remove_column :users, :dropped_projects
end
end
The column is added correctly, but none of the old records are populated with 0. They are nil. I have tried using default=>'0' as well, to no avail. Any idea why this might be happening? (Rails 3.0.3)
Edited to add: When I create a new user it works fine, and everything looks correct. It's just the old users that still have nil for that value in the table.
What happens if you say:
def self.up
add_column :users, :dropped_projects, :integer, :null => false, :default => 0
end
instead? Without the :null=>false you're still allowing NULL in dropped_projects so there's no reason for PostgreSQL to make them 0. Also, I don't think :required is a valid option for add_column; since the options are just a simple Hash and add_column only looks for options it knows about, your stray :required option is silently ignored.
you could do this:
(taken from http://apidock.com/rails/ActiveRecord/Migration)
Using a model after changing its table
Sometimes you’ll want to add a column in a migration and populate it
immediately after. In that case, you’ll need to make a call to
Base#reset_column_information in order to ensure that the model has
the latest column data from after the new column was added. Example:
class AddPeopleSalary < ActiveRecord::Migration
def up
add_column :people, :salary, :integer
Person.reset_column_information
Person.all.each do |p|
p.update_column :salary, SalaryCalculator.compute(p)
end
end
end
I believe this is due to the fact that you are changing the old migration, instead of creating a new.
In this case, the solution is to check the schema file (schema.rb). It does not change automatically, and add
t.integer "dropped_projects", default: 0, null: false

model missing required attr_accessor for 'photo_file_name' when uploading with paperclip and S3 on heroku

Setting up paperclip with S3 in my linux dev environment was a snap -- everything works out of the box. However, I can't get it to work on Heroku.
When I try to do an upload, the log shows:
Processing ItemsController#create (for 72.177.97.9 at 2010-08-26 16:35:14) [POST]
Parameters: {"commit"=>"Create", "authenticity_token"=>"0Hy3qvQBHE1gvFVaq32HMy2ZIopelV0BHbrSeHkO1Qw=", "item"=>{"photo"=>#<File:/home/slugs/270862_4aa601b_4b6f/mnt/tmp/RackMultipart20100826-6286-1256pvc-0>, "price"=>"342", "name"=>"a new item", "description"=>"a new item", "sold"=>"0"}}
Paperclip::PaperclipError (Item model missing required attr_accessor for 'photo_file_name'):
I found one blog post that referenced this error, and it said to add this to my model:
attr_accessor :photo_file_name
attr_accessor :photo_content_type
attr_accessor :photo_file_size
attr_accessor :photo_updated_at
That does indeed make the model missing required attr_accessor for 'photo_file_name' error go away, but it still doesn't work. See my other question for details. As I have figured out that with the attr_accessor lines added to my model the uploads fail even on my dev system, I suspect that is not the right answer.
Found the problem: needed to update the database.
heroku run rake:db:migrate
heroku restart
I had done what I thought would have accomplished the same thing already:
heroku rake db:schema:load
but perhaps that doesn't work or something went wrong in the process.
Error like this occurs if you create wrong column type in migration. When you define new table migration for paperclip, you need to specify t.attachment :name insted of t.string :name. Or add_attachment :table, :name when you add new paperclip column in existed table. And now you don't need to add these attributes in attr_accessor in model.
Well, this message seems to be because the columns it's missing. Try create a migration creating the columns:
class AddPhotoToEvent < ActiveRecord::Migration
def change
add_column :events, :photo_file_name, :string
add_column :events, :photo_content_type, :string
add_column :events, :photo_file_size, :integer
add_column :events, :photo_updated_at, :datetime
end
end
This work for me, here i have a table events with photo