Ruby mysql erreur de connexion

Question

J'utilise MySQL et ruby ​​1.8.6. Je veux me connecter à MySQL donc pour cela j'utilise gem record active. Mon code est

def initialize 

    @db_adapter = "mysql2" 
    @db_host  = "localhost" 
    @db_database = "database_name" 
    @db_user  = "root" 
    @db_password = "root123" 
    con = nil 

end 

def database_connection 
      con = ActiveRecord::Base.establish_connection( 
       :adapter => $db_adapter, 
       :host  => $db_host, 
       :database => $db_database, 
       :user  => $db_user, 
       :password => $db_password 
      ) 

      return con 
end 

mais quand je suis Tring pour le connecter me donne cette erreur

/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.8/lib/active_record/connection_adapters/abstract/connection_specification.rb:76:in `establish_connection': Please install the adapter: `gem install activerecord--adapter` (no such file to load -- active_record/connection_adapters/_adapter) (RuntimeError) 
    from /cmf/samnew/build/Controller/databaseConnection.rb:32:in `database_connection' 
    from controller.rb:23 

Answer 1

Essayez

con = ActiveRecord::Base.establish_connection( 

     :adapter => @db_adapter, 

     :host  => @db_host, 

     :database => @db_database, 

     :user  => @db_user, 

     :password => @db_password 

) 

Answer 2

L'erreur montre la pierre précieuse activerecord--adapter n'est pas installé. Vous pouvez installer la pierre en utilisant la commande

gem install activerecord--adapter.