I have the following migration:
Sequel.migration do
up do
create_table :user_settings do
primary_key :id
String :signature, null: true, text: true
end
alter_table :user_settings do
add_foreign_key :user_id, :users, null: false, on_delete: :cascade
add_index :user_id
end
end
down do
drop_table :user_settings
end
end
This will add default user settings.
The problem I have is that I want to create a row in the user_settings table for every user who is currently in the database that does not have a row, prior to this migration.
I want to check if each user has a row with a a matching user_id in the database and if not, I want to insert some default values.
How can I do this in a migration?
Normally, this kind of things are done using rake task but you need in the migration. I guess you have added the association in the User and UserSetting model and it will be has_one association. You need to create a new migration file
def up
users = User.includes([:user_setting]).where(:user_setting => {:user_id => nil})
users.each do |user|
user.create_user_setting
# OR you can write
# UserSetting.create({:user_id => user.id, :signature => 'your-custom-text'})
end
end
I ended up with this:
Sequel.migration do
up do
existing_settings = SequelAdapter::UserSettings.select(:user_id).to_a
SequelAdapter::User.exclude(id: existing_settings).each do |user|
SequelAdapter::UserSettings.create({user_id: user.id})
end
end
end
Thanks #bachan Smruty who pointed me in the right direction but there is no includes method.
Related
I've been trying to have my rails project only update the user table with the users unique facebook data. However, I can't get the facebook data to populate. I've tried multiple approaches but the end code seems to be hacky and using brute force to update the columns (as well as creating duplicate records)
Here are my examples:
User
class User < ActiveRecord::Base
has_one :facebook
def self.create_with_omniauth(auth)
create! do |user|
user.email = auth['email']
end
end
end
Facebook
class Facebook < ActiveRecord::Base
belongs_to :user
def self.create_with_omniauth(auth)
create! do |fb|
if auth['info']
fb.profile_link = auth['info']['profile_link'] || "test"
end
end
end
Migrations:
class CreateUsers < ActiveRecord::Migration
def change
create_table :users do |t|
t.string :email
t.timestamps null: false
end
end
end
class Facebooks < ActiveRecord::Migration
create_table :facebooks do |f|
f.belongs_to :user, index: true, :unique => true
f.string :profile_link
f.timestamps null: false
end
end
While creating the user:
SessionController (When calling create for user)
def create
auth = request.env["omniauth.auth"]
user = User.where(:provider => auth['provider'],
:uid => auth['uid'].to_s).first || User.create_with_omniauth(auth)
Facebook.create_with_omniauth(auth)
My understanding of Rails ActiveRecord so far... is that if I use "has_one" and "belongs_to" then it should automatically create records in the facebook table if a user table was created?
My expected Data would be:
SELECT * FROM users where id = 1;
id email
1 email#email.com
SELECT * FROM facebooks where user_id = 1;
id user_id profile_link
1 1 facebook.com/profile_link
facebook has no record created at all.
Not sure where I went wrong, I've followed tons of tutorials and hope I can master the active record.
Thanks!
Side Question for #val
def self.facebook_handler(user, auth)
if Facebook.exists?(user_id: id)
user = Facebook.find_by(user_id: id)
user.update(name: me['name'])
user.update(first_name: me['first_name'])
else
create! do |fb|
if me
fb.name = me['name']
fb.user_id = user.id
fb.first_name = me['first_name']
end
end
end
end
--- otherwise it kept inserting new records each time I logged in.
So many moving pieces in activerecord and in Rails. I think you have to go back to your migration and address a few things to set a solid model foundation for the view and controller parts of your MVC.
I see model-type function in the migration you posted, which is not going to serve you well. Migrations should be as flexible as possible, the constraints should be placed on the model.rb.
Migration: Flexible. Basic relationship indices set up.
Model: The
model.rb defines constraints (has_one, belongs_to, etc) and further
embellishes and validates data relationships (:dependent,:required,
etc.)
Your users model looks fine.
class CreateUsers < ActiveRecord::Migration
def change
create_table :users do |t|
t.string :email
t.timestamps null: false
end
end
end
Your facebooks migration should have looked more like this. Create a t.reference and add the index.
class Facebooks < ActiveRecord::Migration
create_table :facebooks do |f|
t.references :user, index: true
f.string :profile_link
f.timestamps null: false
end
add_index :facebooks, [:user_id]
end
Then in your Facebook model you can apply restraints and requirements
facebook.rb
belongs_to :user,
validates :user_id, presence: true, :unique => true
Your user model.rb should include:
has_one :facebook
There are some other questions about your higher level actions in the controller, but I think setting up your model will help you make progress towards your goal.
The model constraints below, along with the index setup looks like it would cause ActiveRecord to ROLLBACK and not add a duplicate facebook record for a given user. But it sounds like duplicates are being added to the facebook table. So, how?
facebook.rb
belongs_to :user,
validates :user_id, presence: true, :unique => true
...
user.rb
has_one :facebook
The 'if' clause you wrote looks to me as if it would be unnecessary if the relationship between user / facebook are set up and working in the model and database table, which makes me think there's a missing validation somewhere.
There's something to try, a model migration (change) on Facebook data description to add a :unique validator to the user_id field of the db table itself. (There's no change_index command, you have to remove and then add.)
remove_index :facebooks, [:user_d]
add_index :facebooks, [:user_id], :unique => true
Try taking your 'if' logic out and see if you're getting dupes. The relationships need to be properly setup before proceeding to the logic in the controller or you will break your head trying to unwind it.
And to your question in the comment, scopes are beautiful for creating collections based on parameters. So, in your user.rb model:
scope :important_thing_is_true, -> { where(:provider => auth['provider'],:uid => auth['uid'].to_s).first) }
Which is referenced by user.important_thing_is_true returns the collection or nil, which then you can test or use in other logic or display, etc. But, if you don't have the dupe records problem, maybe this scope isn't needed.
Here is the Customer:
class CreateCustomer < ActiveRecord::Migration
def self.up
create_table :customers do |t|
t.column :email, :string, :null => false
end
end
def self.down
drop_table :customers
end
end
And this is the customer Info:
class CustomerInfo < ActiveRecord::Migration
def self.up
create_table :statuses do |t|
t.column :statuses, :string, :null => false
end
end
def self.down
drop_table :status
end
end
What I would like to do is the customer and customer Info have a one to one relationship. How can I do it in a new migration? thank you.
When you want a 1 to 1 in Rails, you have to decide which one of the models will store the foreign key. In your case, you probably want status to store the fk, so add an integer column called customer_id to the status table. Then you can add the has_one/belongs_to on Customer and Status. belongs_to always goes on the model with the foreign key.
Also I'm not sure if Rails will like you calling your table with the singular name, so you will probably have to do some extra work if you really want to call it 'status' instead of 'statuses'
You can try following thing in your next migration
add_column :customer_infos , :customer_id , :integer ,:references=>"customers" , :null=>:true
Then you can add the has_one/belongs_to on Customer and Cusomer_infos .
You can also execute an SQL statement.
statement = "ALTER TABLE users CHANGE id id SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT" ActiveRecord::Base.connection.execute(statement)
you can entry manually in your migration
Note this is just an example. The final SQL statement syntax depends on the database.
After creating a table (by migration), I want to insert some entries directly. How must I write a migration for this?
thanks
Don't. If you're looking for seed data, you should use db/seeds.rb and rake db:seed instead. More info in this Railscast.
Side note: Always make sure that the code in db/seeds.rb is idempotent. i.e. It should always be safe to re-run your seeds.
But, if you must insert or modify data inside a migration (there are legitimate use-cases for this), it's best to use SQL statements instead. Your model class isn't guaranteed to still be around in the same form in a future version of your application, and running the migrations from scratch in the future might yield errors if you reference the model class directly.
execute "insert into system_settings (name, label, value) values ('notice', 'Use notice?', 1)"
Update:
This is the right answer: https://stackoverflow.com/a/2667747/7852
Here's an example from ruby on rails api:
class AddSystemSettings < ActiveRecord::Migration
# create the table
def self.up
create_table :system_settings do |t|
t.string :name
t.string :label
t.text :value
t.string :type
t.integer :position
end
# populate the table
SystemSetting.create :name => "notice", :label => "Use notice?", :value => 1
end
def self.down
drop_table :system_settings
end
end
Edit: PLEASE NOTE - Posters above are correct, you should not populate the DB inside migrations. Don't use this to add new data, only to modify data as part of changing the schema.
For many things, using raw SQL will be preferable, but if you need to insert data as part of a migration (for instance, doing data conversion when breaking out a table into multiple tables), and you want some default AR stuff like convenient DB-independent escaping, you can define a local version of the model class:
class MyMigrationSucksALittle < ActiveRecord::Migration
class MyModel < ActiveRecord::Base
# empty guard class, guaranteed to have basic AR behavior
end
### My Migration Stuff Here
### ...
end
Note that this works best for simple cases; since the new class is in a different namespace (MyMigrationSucksALittle::MyModel), polymorphic associations declared in the guard model won't work correctly.
A somewhat more detailed overview of available options is located here: http://railsguides.net/2014/01/30/change-data-in-migrations-like-a-boss/
create a new migration file like
047_add_rows_in_system_settings.rb
class AddRowsInAddSystemSettings < ActiveRecord::Migration
def self.up
SystemSetting.create{:name => "name1", :label => "Use notice?", :value => 1}
SystemSetting.create{:name => "name2", :label => "Use notice?", :value => 2}
end
def self.down
SystemSetting.delete_all
end
end
OR
while creating table
046_system_settings.rb
class AddSystemSettings < ActiveRecord::Migration
def self.up
create_table :system_settings do |t|
t.string :name
t.string :label
t.text :value
t.string :type
t.integer :position
end
SystemSetting.create :name => "notice", :label => "Use notice?", :value => 1
end
def self.down
drop_table :system_settings
end
end
Ref:- http://api.rubyonrails.org/classes/ActiveRecord/Migration.html
Let's say I create a table in a Rails migration, specifying to omit the ID column:
create_table :categories_posts, :id => false do |t|
t.column :category_id, :integer, :null => false
t.column :post_id, :integer, :null => false
end
Later I decide I want to add an ID column as a primary key so I create a new migration:
class ChangeCategoriesToRichJoin < ActiveRecord::Migration
def self.up
add_column :categories_posts, :id, :primary_key
end
def self.down
remove_column :categories_posts, :id
end
end
But when I look at the table after I migrate, it looks like this:
category_id
post_id
id
The id column is in the last position in the table, whereas normally an id column would be first.
Is there a way to change the ChangeCategoriesToRichJoin migration to insist on the id column being created BEFORE the category_id column in the table?
Or do I need to drop the table and add the column in the "create table" definition?
Use :after => :another_column_name, e.g.:
change_table :users do |t|
t.integer :like_count, :default => 0, :after => :view_count
end
I haven't been able to put the columns in order, myself, but with Rails you can rollback, alter the old migration file to add the new columns in the order you want, then re-migrate up the old migration including the new field. It's not exactly ideal, but the ability to migrate and rollback easily, it can work if you're OCD enough to require column order. :P
I am not an expert, but I've read a lot of Rails documentation (and very recently) and can't recall finding a solution for this.
Took me a while to track down this error but I finally found out why. I am modeling a card game using the Rails framework. Currently my database looks (mostly) like this:
cards cards_games games
----- ----------- -----
id id id
c_type card_id ...
value game_id other_stuff
And the Rails ActiveRecord card.rb and game.rb currently look like this
#card.rb
class Card < ActiveRecord::Base
has_and_belongs_to_many :player
has_and_belongs_to_many :game
has_and_belongs_to_many :cardsInPlay, :class_name => "Rule"
end
#game.rb
class Game < ActiveRecord::Base
has_and_belongs_to_many :cards
has_many :players
has_one :rules, :class_name => Rule
end
When I attempt to run a game and there are multiple games (more than 1), I get the error
ActiveRecord::StatementInvalid in GameController#start_game
# example
Mysql::Error: Duplicate entry '31' for key 1: INSERT INTO `cards_games` (`card_id`, `id`, `game_id`) VALUES (31, 31, 7)
Every time the action fails, cardid == id. This, I assume, has something with how Rails inserts the data into the database. Since there is no cardsgames object, I think it is just pulling card_id into id and inserting it into the database. This works fine until you have two games with the same card, which violates the primary key constraint on cardsgames. Being affluent with databases, my first solution to this problem was to try to force rails to follow a "real" definition of this relationship by dropping id and making cardid and gameid a primary key. It didn't work because the migration couldn't seem to handle having two primary keys (despite the Rails API saying that its okay to do it.. weird). Another solution for this is to omit the 'id' column in the INSERT INTO statement and let the database handle the auto increment. Unfortunately, I don't know how to do this either.
So, is there another work-around for this? Is there some nifty Rails trick that I just don't know? Or is this sort of structure not possible in Rails? This is really frustrating because I know what is wrong and I know several ways to fix it but due to the constraints of the Rail framework, I just cannot do it.
has_and_belongs_to_many implies a join table, which must not have an id primary key column. Change your migration to
create_table :cards_games, :id => false do ...
as pointed out by Matt. If you will only sleep better if you make a key from the two columns, create a unique index on them:
add_index :cards_games, [ :card_id, :game_id ], :unique => true
Additionally, your naming deviates from Rails convention and will make your code a little harder to read.
has_and_belongs_to_many defines a 1:M relationship when looking at an instance of a class. So in Card, you should be using:
has_and_belongs_to_many :players
has_and_belongs_to_many :games
Note plural "players" and "games". Similarly in Game:
has_one :rule
This will let you drop the unnecessary :class_name => Rule, too.
To drop the ID column, simply don't create it to begin with.
create_table :cards_rules, :id => false do ...
See Dr. Nics composite primary keys
http://compositekeys.rubyforge.org/
I found the solution after hacking my way through. I found out that you can use the "execute" function inside of a migration. This is infinitely useful and allowed me to put together an non-elegant solution to this problem. If anyone has a more elegant, more Rails-like solution, please let me know. Here's the solution in the form of a migration:
class Make < ActiveRecord::Migration
def self.up
drop_table :cards_games
create_table :cards_games do |t|
t.column :card_id, :integer, :null => false
t.column :game_id, :integer, :null => false
end
execute "ALTER TABLE cards_games DROP COLUMN id"
execute "ALTER TABLE cards_games ADD PRIMARY KEY (card_id, game_id)"
drop_table :cards_players
create_table :cards_players do |t|
t.column :card_id, :integer, :null => false
t.column :player_id, :integer, :null => false
end
execute "ALTER TABLE cards_players DROP COLUMN id"
execute "ALTER TABLE cards_players ADD PRIMARY KEY (card_id, player_id)"
drop_table :cards_rules
create_table :cards_rules do |t|
t.column :card_id, :integer, :null => false
t.column :rule_id, :integer, :null => false
end
execute "ALTER TABLE cards_rules DROP COLUMN id"
execute "ALTER TABLE cards_rules ADD PRIMARY KEY (card_id, rule_id)"
end
def self.down
drop_table :cards_games
create_table :cards_games do |t|
t.column :card_id, :integer
t.column :game_id, :integer
end
drop_table :cards_players
create_table :cards_players do |t|
t.column :card_id, :integer
t.column :player_id, :integer
end
drop_table :cards_rules
create_table :cards_rules do |t|
t.column :card_id, :integer
t.column :rule_id, :integer
end
end
end
You might want to check out this foreign_key_migrations plugin