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Diffstat (limited to 'guides/source/active_record_basics.md')
| -rw-r--r-- | guides/source/active_record_basics.md | 42 |
1 files changed, 21 insertions, 21 deletions
diff --git a/guides/source/active_record_basics.md b/guides/source/active_record_basics.md index 1f25c6ae95..a184f0753d 100644 --- a/guides/source/active_record_basics.md +++ b/guides/source/active_record_basics.md @@ -48,10 +48,10 @@ overall database access code. Active Record gives us several mechanisms, the most important being the ability to: -* Represent models and their data -* Represent associations between these models -* Represent inheritance hierarchies through related models -* Validate models before they get persisted to the database +* Represent models and their data. +* Represent associations between these models. +* Represent inheritance hierarchies through related models. +* Validate models before they get persisted to the database. * Perform database operations in an object-oriented fashion. Convention over Configuration in Active Record @@ -78,15 +78,15 @@ of two or more words, the model class name should follow the Ruby conventions, using the CamelCase form, while the table name must contain the words separated by underscores. Examples: -* Database Table - Plural with underscores separating words (e.g., `book_clubs`) +* Database Table - Plural with underscores separating words (e.g., `book_clubs`). * Model Class - Singular with the first letter of each word capitalized (e.g., -`BookClub`) +`BookClub`). | Model / Class | Table / Schema | | ------------- | -------------- | | `Post` | `posts` | | `LineItem` | `line_items` | -| `Deer` | `deer` | +| `Deer` | `deers` | | `Mouse` | `mice` | | `Person` | `people` | @@ -101,11 +101,11 @@ depending on the purpose of these columns. fields that Active Record will look for when you create associations between your models. * **Primary keys** - By default, Active Record will use an integer column named - `id` as the table's primary key. When using [Rails + `id` as the table's primary key. When using [Active Record Migrations](migrations.html) to create your tables, this column will be automatically created. -There are also some optional column names that will create additional features +There are also some optional column names that will add additional features to Active Record instances: * `created_at` - Automatically gets set to the current date and time when the @@ -116,7 +116,7 @@ to Active Record instances: locking](http://api.rubyonrails.org/classes/ActiveRecord/Locking.html) to a model. * `type` - Specifies that the model uses [Single Table - Inheritance](http://api.rubyonrails.org/classes/ActiveRecord/Base.html) + Inheritance](http://api.rubyonrails.org/classes/ActiveRecord/Base.html#label-Single+table+inheritance). * `(association_name)_type` - Stores the type for [polymorphic associations](association_basics.html#polymorphic-associations). * `(table_name)_count` - Used to cache the number of belonging objects on @@ -181,18 +181,18 @@ definition: ```ruby class FunnyJoke < ActiveSupport::TestCase - set_fixture_class funny_jokes: 'Joke' + set_fixture_class funny_jokes: Joke fixtures :funny_jokes ... end ``` It's also possible to override the column that should be used as the table's -primary key using the `ActiveRecord::Base.set_primary_key` method: +primary key using the `ActiveRecord::Base.primary_key=` method: ```ruby class Product < ActiveRecord::Base - set_primary_key "product_id" + self.primary_key = "product_id" end ``` @@ -253,7 +253,7 @@ user = User.first ```ruby # return the first user named David -david = User.find_by_name('David') +david = User.find_by(name: 'David') ``` ```ruby @@ -270,7 +270,7 @@ Once an Active Record object has been retrieved, its attributes can be modified and it can be saved to the database. ```ruby -user = User.find_by_name('David') +user = User.find_by(name: 'David') user.name = 'Dave' user.save ``` @@ -279,7 +279,7 @@ A shorthand for this is to use a hash mapping attribute names to the desired value, like so: ```ruby -user = User.find_by_name('David') +user = User.find_by(name: 'David') user.update(name: 'Dave') ``` @@ -297,7 +297,7 @@ Likewise, once retrieved an Active Record object can be destroyed which removes it from the database. ```ruby -user = User.find_by_name('David') +user = User.find_by(name: 'David') user.destroy ``` @@ -343,7 +343,7 @@ Migrations Rails provides a domain-specific language for managing a database schema called migrations. Migrations are stored in files which are executed against any -database that Active Record support using `rake`. Here's a migration that +database that Active Record supports using `rake`. Here's a migration that creates a table: ```ruby @@ -368,6 +368,6 @@ Rails keeps track of which files have been committed to the database and provides rollback features. To actually create the table, you'd run `rake db:migrate` and to roll it back, `rake db:rollback`. -Note that the above code is database-agnostic: it will run in MySQL, postgresql, -Oracle and others. You can learn more about migrations in the [Active Record -Migrations guide](migrations.html) +Note that the above code is database-agnostic: it will run in MySQL, +PostgreSQL, Oracle and others. You can learn more about migrations in the +[Active Record Migrations guide](migrations.html). |