query in rails3.1

I got an issue in rails3.1, in the rails console

a=User.find_by_name 'castiel'
a.name #output: castiel

a=User.where "name like 'c%'"
a.name #output: User
#both query got the same thing,but why the second one output 'User'

I used a new feature in rails3.1 which is about authentication, you know the one that introduced in railscast episode authentication-in-rails3.1,maybe it's got something to do with this,just thought it might be good to let u know the开发者_JAVA百科 circumstances here.

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The issue is that find_by_name and where are not returning the same thing. find_by_name will find the first User that matches your query. where will return a collection of Users that match your query.

In your first example, the result is a single User object, so a.name gives you "castiel".

a=User.find_by_name 'castiel'
# 'a' will be something like #<User id:..., name: "castiel"...>
a.name #output: castiel

In the second example, however, the result is essentially an array of User objects. If you call a.name, it will return the name of the model it holds: User.

a=User.where "name like 'c%'"
# 'a' might be something like [#<User id:..., name: "castiel"...>] 
a.name #output: User

Even though using where probably only returns you one result, it's still wrapped in an array.

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That's because when you use where it will return a ActiveRecord::Relation object and not a User object. find_by_<blahblah> method returns an instance of the Model.