atchyutn
commented
5 years ago Sample Usage Examples:
belongs_to & has_many association: Relation: User-> has_many posts Post-> belongs to user
creation: user = User.new user.name = "Karthik" user.save
post = Post.new post.title = "First post" post.user_id = user.id post.save
Results: User.find(user.id).posts-> posts Post.find(post.id).user-> user
one-to-one association: User has_one address Address belongs_to user
creation: user = User.new user.name = "Karthik" user.save
address = Address.new address.city="Hyderabad" Address.find(address.id).user_id = user.id
User.find(user_id).address Address.find(address_id).user
Many-to-Many Association: Has and belongs to many associations: Relation: User -> has_and_belongs_to_many :events Event-> has_and_belongs_to_many :users
Creation: e1 = Event.new e1.title = "Event one" e1.save
e2 = Event.new e2.title = "Event two" e2.save
user = User.new user.name = "Karthik" user.save
user.events << e1 user.events << e2
Result: user.events -> e1, e2 e1.users -> u1, u2
Has Many through association: Relations: Enrollment-> belongs_to :game, belongs_to :user User->has_many :enrollments, has_many :games, through: :enrollments Game->has_many :enrollments, has_many :users, through: :enrollments
Creation: g1 = Game.new g1.title = "GTA" g1.save
u1 = User.new u1.name = "Karthik" u1.save
e1 = Enrollment.new e1.game_id = g1.id e1.user_id = u1.id e1.category = "firing games" e1.save
Result: u1.enrollments -> e1 g1.enrollments -> e1 e1.category-> firing games
Has One through Association: Relations: User->has_one :wallet, has_one :payment_history, through: :wallet Wallet->belongs_to :user, has_one :payment_history PaymentHistory->belongs_to :purse
Creation:
user = User.new user.name = "Karthik" user.save
wallet = Wallet.new wallet.funds = 100 wallet.user_id = user.id wallet.save
ph = PaymentHistory.new ph.wallet_id = wallet.id ph.save
Results: user.payment_history-> ph user.wallet->wallet wallet.user->user
Feature Request Add installations setups, Usage Examples
Solution Description Add Usage Instructions, Examples that can be run in the rails console.