diff options
Diffstat (limited to 'activerecord/lib/active_record/base.rb')
| -rw-r--r-- | activerecord/lib/active_record/base.rb | 50 |
1 files changed, 4 insertions, 46 deletions
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb index aab832c2f7..bf5793d454 100644 --- a/activerecord/lib/active_record/base.rb +++ b/activerecord/lib/active_record/base.rb @@ -162,12 +162,9 @@ module ActiveRecord #:nodoc: # # Dynamic attribute-based finders are a cleaner way of getting (and/or creating) objects # by simple queries without turning to SQL. They work by appending the name of an attribute - # to <tt>find_by_</tt>, <tt>find_last_by_</tt>, or <tt>find_all_by_</tt> and thus produces finders - # like <tt>Person.find_by_user_name</tt>, <tt>Person.find_all_by_last_name</tt>, and - # <tt>Payment.find_by_transaction_id</tt>. Instead of writing - # <tt>Person.where(user_name: user_name).first</tt>, you just do <tt>Person.find_by_user_name(user_name)</tt>. - # And instead of writing <tt>Person.where(last_name: last_name).all</tt>, you just do - # <tt>Person.find_all_by_last_name(last_name)</tt>. + # to <tt>find_by_</tt> # like <tt>Person.find_by_user_name</tt>. + # Instead of writing # <tt>Person.where(user_name: user_name).first</tt>, you just do + # <tt>Person.find_by_user_name(user_name)</tt>. # # It's possible to add an exclamation point (!) on the end of the dynamic finders to get them to raise an # <tt>ActiveRecord::RecordNotFound</tt> error if they do not return any records, @@ -180,46 +177,7 @@ module ActiveRecord #:nodoc: # # It's even possible to call these dynamic finder methods on relations and named scopes. # - # Payment.order("created_on").find_all_by_amount(50) - # Payment.pending.find_last_by_amount(100) - # - # The same dynamic finder style can be used to create the object if it doesn't already exist. - # This dynamic finder is called with <tt>find_or_create_by_</tt> and will return the object if - # it already exists and otherwise creates it, then returns it. Protected attributes won't be set - # unless they are given in a block. - # - # # No 'Summer' tag exists - # Tag.find_or_create_by_name("Summer") # equal to Tag.create(name: "Summer") - # - # # Now the 'Summer' tag does exist - # Tag.find_or_create_by_name("Summer") # equal to Tag.find_by_name("Summer") - # - # # Now 'Bob' exist and is an 'admin' - # User.find_or_create_by_name('Bob', age: 40) { |u| u.admin = true } - # - # Adding an exclamation point (!) on to the end of <tt>find_or_create_by_</tt> will - # raise an <tt>ActiveRecord::RecordInvalid</tt> error if the new record is invalid. - # - # Use the <tt>find_or_initialize_by_</tt> finder if you want to return a new record without - # saving it first. Protected attributes won't be set unless they are given in a block. - # - # # No 'Winter' tag exists - # winter = Tag.find_or_initialize_by_name("Winter") - # winter.persisted? # false - # - # To find by a subset of the attributes to be used for instantiating a new object, pass a hash instead of - # a list of parameters. - # - # Tag.find_or_create_by_name(name: "rails", creator: current_user) - # - # That will either find an existing tag named "rails", or create a new one while setting the - # user that created it. - # - # Just like <tt>find_by_*</tt>, you can also use <tt>scoped_by_*</tt> to retrieve data. The good thing about - # using this feature is that the very first time result is returned using <tt>method_missing</tt> technique - # but after that the method is declared on the class. Henceforth <tt>method_missing</tt> will not be hit. - # - # User.scoped_by_user_name('David') + # Payment.order("created_on").find_by_amount(50) # # == Saving arrays, hashes, and other non-mappable objects in text columns # |