Remove rails model after migration
ruby, ruby-on-rails, ruby-on-rails-3
Solution
rails d model name
This just deletes the model and not the migration you have run (which created the table in the database).
If you want to delete both the model and the tables, you will have to do the following
rake db:rollback
rails d model name
Problem
It seems strange to me, that creation of model, running migration, destroying it, and creating again same model reports SQL exception: ``` project|master ⇒ rails g model name name invoke active_record create db/migrate/20130417185814_create_names.rb create app/models/name.rb project|master⚡ ⇒ rake db:migrate == CreateNames: migrating ==================================================== -- create_table(:names) -> 0.0020s == CreateNames: migrated (0.0021s) =========================================== project|master⚡ ⇒ rails d model name invoke active_record remove db/migrate/20130417185814_create_names.rb remove app/models/name.rb project|master⚡ ⇒ rake db:migrate project|master⚡ ⇒ rails g model name test invoke active_record create db/migrate/20130417185845_create_names.rb create app/models/name.rb project|master⚡ ⇒ rake db:migrate == CreateNames: migrating ==================================================== -- create_table(:names) rake aborted! An error has occurred, this and all later migrations canceled: SQLite3::SQLException: table "names" already exists: CREATE TABLE "names" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, "test" varchar(255), "created_at" datetime NOT NULL, "updated_at" datetime NOT NULL) /path/project/db/migrate/20130417185845_create_names.rb:3:in `change' -- create_table("names", {:force=>true}) -> 0.0100s -- initialize_schema_migrations_table() -> 0.0025s -- assume_migrated_upto_version(20130417185814, ["/path/project/db/migrate"]) -> 0.0010s You have 1 pending migrations: 20130417185845 CreateNames Run `rake db:migrate` to update your database then try again. ``` Maybe, I doing something wrong? Migration has code for deleting table - does it may be used only for rollback? Solution Delete model and database table and generate a new one is pretty easy: - Create model: `rails g model user name` - Do migrations: `rake db:migrate` - Implement something, suddenly remember that you need to delete model - Revert specific migration: `rake db:migrate:down VERSION=20130417185814`, where `20130417185814` is migration id (can be seen in rake db:migrate:status) - Remove model: `rails d model user` - Suddenly remember that you need this model, but with other fields - Create model: `rails g model user email group:references` - Successfully migrate database: `rake db:migrate`