Rails session

25/12/2010  --saturday

today we celebrate christmas in our office and we cut the cake and celebrate lots of fun in our office

today our guru chandrashekar sir told the introduction to rails

rails features

today our sir told class responsibilites colloborators

crc (vs) data flow diagram

sir told the difference between them

to generate a model in rails
--------------------------------

                rails generate model user

name:string        email:string  password:string

to check the db
---------------
                     less config | database.yml

rake db:migrate

to check db exists (or) not
---------------------------

                 rails dbconsole


rails 3 has an inbuilt nice feature of "sqlite" light weighted database

sqlite> .tables           this command will show the list of all tables

sqlite>.schema users      to see the users structure

sqlite>.quit --------> to quit the sqlite

to start a server
------------------
                       rails server

another terminal
---------------------------
                               cd rails  again cd tu

like Irb rails console
-----------------------

                            u= user.new
                            u.name="john"
                            u.password="john123"
                            u.email="john@doe.com"
                            u
                            u.save!

the above lines stating that creating a new user and assigning a password and email id
and save the rails application

another terminal
-----------------------
                         to show rails console
                    
               SELECT *from users
            
                sqlite>
                        u=user.new:name=>'smith':password=>'smith123':email=>'smith@yahoo.com'
                        u.save

                SELECT *from users


 u=user.find-by-name("john")
 users=users.find:all        //it will find all records

      
users[0].name
users[1].name

users=user.find:all,:conditions=>{:name=>'john'}

users=user.find:first,:conditions=>{:name=>'john'}

-----------------------------------------------------------------

vi app/models/user.rb

class User<activeRecord ::Base

            .validates:name,:presence=>true
 
            .validates:name,:uniqueness=>true
                                       
             .validates:name,:length=>{:maximum=>32}

end


and sir also told ....best  guides to ruby on rails

 www.api.rubyonrails.org