creating a simple model with a migration like the following will break the rake db:migrate tasks:
class CreateProducts < ActiveRecord::Migration
def change
create_table :products do |t|
t.string :title
t.float :price, :default => "0.00"
t.string :currency, :default => "€"
t.timestamps
end
end
end
Exchanging the Euro sign with EUR fixes the issue temporary but in general I'd love to understand how I could work with € as default value there.
Cheers
Put this on the first line of your migration file:
# encoding: utf-8
Related
I am trying to add user:references onto my already existing model. This is what I originally wrote:
rails g model Post title:string description:text
I do this to add the user:references by running rails generate migration add_user_to_posts user:references, I am receiving this error upon running rake db:migrate:
-- create_table(:users)
rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:
SQLite3::SQLException: table "users" already exists
I am reading the error and I understand I already have a User model, however, I want to add this attribute to the Post model, not the User model.
Db file:
Posts:
class CreatePosts < ActiveRecord::Migration[5.0]
def change
create_table :posts do |t|
t.string :title
t.text :description
t.timestamps
end
end
end
Trying to add the user to posts:
class AddUserToPosts < ActiveRecord::Migration[5.0]
def change
add_reference :posts, :user, foreign_key: true
end
end
Users:
class CreateUsers < ActiveRecord::Migration[5.0]
def change
create_table :users do |t|
t.string :name
t.string :uid
t.string :avatar_url
t.timestamps
end
add_index :users, :uid
end
end
However, rake db:migrate gives me the error above.
Got a issue when i run rake db:migrate. The mistake message is like
-- create_table(:addresses)
-> 0.1792s
-- contact_id()
rake aborted!
An error has occurred, this and all later migrations canceled:
undefined local variable or method `contact_id' for #<CreateAddresses:0x00000001724718>/var/lib/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/migration.rb:465:in `block in method_missing'
And i used command before migrate
rails g model address street:string city:string region:string postalcode:string country:string contact_id:integer
And my migration file :
class CreateAddresses < ActiveRecord::Migration
def change
create_table :addresses do |t|
t.string :street
t.string :city
t.string :region
t.string :postalcode
t.string :country
t.integer :contact_id
t.timestamps
end
add_index :addresses, [contact_id, :create_at]
end
end
Could anybody tell where i made mistake please? Thank you a lot.
you are missing : before contact_id:
add_index :addresses, [:contact_id, :create_at]
Is there a way to specify a database level uniqueness constraint on a field in a Rails 3.1+ migration? I know ActiveRecord's validates_uniqueness_of would work, but I'm curious to know if this can be specified elsewhere.
For example, in order to specify that the 'login' field should be unique in a migration such as ...
class CreateUsers < ActiveRecord::Migration
def change
create_table :users do |t|
t.string :name
t.string :login
t.timestamps
end
end
end
... I'd like to add an option like :unique => true.
There's nothing mentioned in the Documentation so I assume that's not a great place/way to do things, but does anyone know how this might be achieved (even if it's manually added to the resulting schema)? Or is validates_uniqueness_of the preferred way to go?
You can add unique index so:
def change
create_table :users do |t|
t.string :name
t.string :login
t.timestamps
end
add_index :users, :login, :unique => true
end
I'm not able to generate string fields with a specified length in a migration. They are always created with 255 character-length.
Anyone knows?
I think you're looking for the :limit option:
class CreateUser < ActiveRecord::Migration
def change
create_table :users do |t|
t.string :name, :limit => 10
end
end
end
Reference
when i deal with a migrate data,i want to make each record unique in the table the migrate file make.here is my migrate file:
def self.up
create_table :rbac_mandata do |t|
t.integer :mandator_id
t.integer :mandatarius_id
t.integer :permission_id
t.timestamps
end
add_index :rbac_mandata, [:mandator_id, :mandatarius_id, :permission_id], :unique => true
end
when i execute rake task and find it not work.but when i change it to this,it was done:
def self.up
create_table :rbac_mandata do |t|
t.integer :mandator_id
t.integer :mandatarius_id
t.integer :permission_id
t.timestamps
end
add_index :rbac_mandata, [:mandator_id, :permission_id], :unique => true
end
The generated index name is probably too long, it's probably over 64 characters. Just define the name manually and it'll go through fine, like this...
add_index :rbac_mandata, [:mandator_id, :mandatarius_id, :permission_id], :unique => true, :name => 'my_index_name_here'