生成一个使用数据库中现有数据的模型

Question

Im making an application with a pre-existing database, I set up the database.yml to use the database.

database.yml

   development:
  adapter: mysql2
  encoding: utf8
 # database: ttlem_demo_development
  database: ttle
  pool: 5
  username: root
  password:
  socket: /tmp/mysql.sock

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  adapter: mysql2
  encoding: utf8
  database: ttlem_demo_test
  pool: 5
  username: root
  password:
  socket: /tmp/mysql.sock

production:
  adapter: mysql2
  encoding: utf8
  database: ttlem_demo_production
  pool: 5
  username: root
  password:
  socket: /tmp/mysql.sock

I only want one table out of the database it is called account views, I try to generate a scaffold for this with all the correct fields but it tells me i need to migrate (when i render it in the browser), if i migrate i wont be able to use the existing data, is this correct? How can i make a model that will use the existing data and fields?

Thank you for all your help :)

Answer 1

Two things to try:... #1 Run your scaffold without a migration so it doesn't think you're missing one.

rails g scaffold yourmodelname fieldone:fieldtype ... etc  --no-migration

#2 If that doesn't work you can go the long way round but dumping and reloading with a valid schema version number

Add this db to yml to your gemfile:

gem 'yaml_db', github: 'jetthoughts/yaml_db', ref: 'fb4b6bd7e12de3cffa93e0a298a1e5253d7e92ba'

It works for either rails 3 or rails 4.

Do a schema dump of your current database so you'll get a schema.rb with a valid version number.

bundle exec rake db:schema:dump

Now that you have a valid schema dump your data.

 bundle exec rake db:data:dump

Drop your database (you can do it manually using the mysql commands if you prefer or run rake db:drop)

Now recreate it with your schema file.

 bundle exec rake db:schema:load

Now add back your data

bundle exec rake db:data:load

Start your server and assuming your correctly matched all your data fields in your model (so the proper strong parameters are set from your scaffold) you should be good.