Rails app with seeded postgresql db

rails_postgres.md

Creating a rails app with a prepopulated postgres db

Prerequisite: make sure Postgres is started! You should see the elephant icon in the menu bar

Plural for table names and controller names, singular for models

1. Create a new project using postgresql.

rails new projectName -d postgresql

2. Create the empty DB.

rake db:create

rake -T - List all rake commands

3. Generate db/migrate/timestamp_create_tableName.rb stub file.

rails generate migration create_pluralised_tablename # can also use CreatePluralisedTablename

Fill in column data and type so rails can create the schema. This is like writing .sql scripts.

create_table :pluralised_tablename do |t| # must use camel case
    t.text :name # no commas after each field!
    ...
    t.timestamps
end

4. Create the table in postgres

rake db:migrate

Confirm the table data in db/schema.rb. If you make a mistake, undo the last migrate with rake db:rollback

5. Hook up active record. Create app/models/singularisedModelname.rb and add

class SingularisedModelname < ActiveRecord::Base # first letter of class name must be capitalised
end

Run annotate to update model with schema comments

6. Pre-populate DB by adding data to db/seeds.rb

Modelname.destroy_all # clobber everything in DB first
Modelname.create(:colName => data, ...) # active record method to create new row data

7. Add seed data to DB

rake db:seed

8. Run rails console and Modelname.all to check data is all there. If you've mispelt/forgotten a field, update the migrate file (step 3) then do

rake db:drop
rake db:create
rake db:migrate
rake db:seed

9. Generate RESTful routes. Add to config/routes.rb

resources :pluralised_tablename

10. Generate controller actions and views.

rails generate controller Pluralised_controllername action1 action2 # eg. Artists index new edit show

Remove redundant routes from config/routes.rb

To add a foreign key to your table:

rails generate migration add_singularised_tablename_id_to_pluralised_tablename # eg. add_artist_id_to_works

This should add artist_id:integer to the migrate file.