Hi,
As much as I like Rails, I’m not very proficient at databases/schemas
and
migrations.
Right now the data inside the db does not matter as nothing has been
populated yet, I’m just trying to get my app working.
I used scaffolding to generate my models, controllers, views etc.
Originally I wrote the app to use sqlite3, but now that I want to move
my
app to a production environment with mysql or even postgres, I keep on
getting an error involving foreign keys.
It appears there is a syntax issue somewhere with author_id inside of
the
article model
When I try to migrate to the database, this is the output I get
user@localhost:~/myapp/current/db$ rake db:drop
(in /home/myuser/myapp/current)
user@localhost:~/myapp/current/db$ rake db:create
(in /home/myuser/myapp/current)
user@localhost:~/myapp/current/db$ rake db:migrate
(in /home/myuser/myapp/current)
== 20150321171546 DeviseCreateUsers: migrating
================================
– create_table(:users)
-> 0.0080s
– add_index(:users, :email, {:unique=>true})
-> 0.0249s
– add_index(:users, :reset_password_token, {:unique=>true})
-> 0.0232s
== 20150321171546 DeviseCreateUsers: migrated (0.0571s)
== 20150321171548 AddNameToUsers: migrating
===================================
– add_column(:users, :name, :string)
-> 0.0109s
== 20150321171548 AddNameToUsers: migrated (0.0114s)
== 20150321172618 CreateArticles: migrating
===================================
– create_table(:articles)
rake aborted!
StandardError: An error has occurred, all later migrations canceled:
Mysql2::Error: Can't create table 'myapp_dev.#sql-50a3_a4' (errno:
150): ALTER TABLE articles ADD CONSTRAINT fk_rails_e74ce85cbc
FOREIGN KEY (author_id)
REFERENCES authors (id)
/usr/local/rvm/gems/ruby-2.2.0/gems/activerecord-4.2.1/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:299:in
`query’
/usr/local/rvm/gems/ruby-2.2.0/gems/activerecord-4.2.1/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:299:in
`block in execute’
/usr/local/rvm/gems/ruby-2.2.0/gems/activerecord-4.2.1/lib/active_record/connection_adapters/abstract_adapter.rb:473:in
`block in log’
/usr/local/rvm/gems/ruby-2.2.0/gems/activesupport-4.2.1/lib/active_support/notifications/instrumenter.rb:20:in
`instrument’
Here are what my migrations and schema.rb looks like
user@localhost:~/myapp/current/db/migrate$ cat
20150321215751_create_authors.rb
class CreateAuthors < ActiveRecord::Migration
def change
create_table :authors do |t|
t.string :name
t.string :hashtags
t.string :avatar
t.string :email
t.timestamps null: false
end
end
end
user@localhost:~/myapp/current/db/migrate$ cat
20150321172618_create_articles.rb
class CreateArticles < ActiveRecord::Migration
def change
create_table :articles do |t|
t.belongs_to :author, index: true, foreign_key: true
t.string :title
t.string :bannerurl
t.string :thumbnailurl
t.text :content
t.timestamps null: false
end
end
end
user@localhost:~/myapp/current/db$ cat schema.rb
ActiveRecord::Schema.define(version: 20150321171548) do
create_table "authors", force: :cascade do |t|
t.string "name"
t.string "hashtags"
t.string "avatar"
t.string "email"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
create_table "articles", force: :cascade do |t|
t.integer "author_id", limit: 4
t.string "title", limit: 255
t.string "bannerurl", limit: 255
t.string "thumbnailurl", limit: 255
t.text "content", limit: 65535
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
add_index "articles", ["author_id"], name:
“index_articles_on_author_id”, using: :btree
end