Question

I’m having problems changing the data type of a particular model’s attribute (i.e. money). Money was an integer — I’m trying to use a migration to change it to a decimal, with a precision of 5 and a scale of 2. Upon doing the migration, everything looks OK in console (i.e. it appears the migration worked), but when I go to change a value to a decimal in the web app, I get an ‘Invalid value’ message. The error appears to be taking place on the client-side for some reason (it’s a js popup)? I didn’t include any client-side validations though. Here are the steps I take:

First, I generate the migration:

>rails generate migration change_data_type_for_user_money

Then, I edit the migration. Here’s what it looks like:

class ChangeDataTypeForUserMoney < ActiveRecord::Migration
  def self.up
    change_table :users do |t|
      t.change :money, :decimal, :precision => 5, :scale => 2
    end
  end

  def self.down
    change_table :users do |t|
      t.change :money, :decimal, :precision => 5, :scale => 2
    end
  end
end

Then I do a ‘rake db:migrate’

What is odd is that zero’s following the decimal point appear and are fine (e.g. 100.00 is OK, but 100.50 is when I get the error)

Also, here’s the model:

class User < ActiveRecord::Base
  attr_accessible :money, :name

  validates :money, :name, :presence => true
  validates :money, :numericality => true
end

And the _from view:

<%= form_for(@user) do |f| %>
  <% if @user.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@user.errors.count, "error") %> prohibited this user from being saved:</h2>

      <ul>
      <% @user.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :name %><br />
    <%= f.text_field :name %>
  </div>
  <div class="field">
    <%= f.label :money %><br />
    $<%= f.number_field :money %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

Any thoughts? Thanks in advance for your help!

Answer 1

Not sure, but try:

class ChangeDataTypeForUserMoney < ActiveRecord::Migration
  def change
    change_table :users do |t|
      t.decimal :money, :precision => 5, :scale => 2
    end
  end
end

EDIT: Turned out the issue was not with migration at all, but the validator. The solution was to change: <%= f.number_field :money %> to <%= f.text_field :money %> as per my comment below.