activerecord1.rb

activerecord1.rb

field = Movie.new(:title => 'Title',
  :release_date => '21-Apr-89', :rating => 'PG') #just makes a new object, doesn't add it to DB
field.save! #now it's saved in DB, the '!' means an exception will be thrown if it can't be saved
field.title = 'New' #changes the object field only, it is still 'Title' in the DB unless we save again
####  Read
pg_movies = Movie.where("rating = 'PG'")
ancient_movies = Movie.where('release_date < :cutoff and rating = :rating',
  :cutoff => 'Jan 1, 2000', :rating => 'PG')
####  Another way to read
Movie.find(3)  # exception if key not found
####  Find returns an enumerable
Movie.where('rating = "PG"').each do |mov|
  mov.destroy #after calling destroy, it's gone from DB. 
  #You can still inspect the object but trying to modify it 
  #or call a method that would access db would raise exception
end