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Diffstat (limited to 'railties/guides/source/migrations.textile')
| -rw-r--r-- | railties/guides/source/migrations.textile | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/railties/guides/source/migrations.textile b/railties/guides/source/migrations.textile index 89aa007279..0d13fbc10a 100644 --- a/railties/guides/source/migrations.textile +++ b/railties/guides/source/migrations.textile @@ -546,7 +546,7 @@ Schema files are also useful if you want a quick look at what attributes an Acti h4. Types of Schema Dumps -There are two ways to dump the schema. This is set in +config/environment.rb+ by the +config.active_record.schema_format+ setting, which may be either +:sql+ or +:ruby+. +There are two ways to dump the schema. This is set in +config/application.rb+ by the +config.active_record.schema_format+ setting, which may be either +:sql+ or +:ruby+. If +:ruby+ is selected then the schema is stored in +db/schema.rb+. If you look at this file you'll find that it looks an awful lot like one very big migration: @@ -584,13 +584,11 @@ h3. Active Record and Referential Integrity The Active Record way claims that intelligence belongs in your models, not in the database. As such, features such as triggers or foreign key constraints, which push some of that intelligence back into the database, are not heavily used. -Validations such as +validates_uniqueness_of+ are one way in which models can enforce data integrity. The +:dependent+ option on associations allows models to automatically destroy child objects when the parent is destroyed. Like anything which operates at the application level these cannot guarantee referential integrity and so some people augment them with foreign key constraints. +Validations such as +validates :foreign_key, :uniqueness => true+ are one way in which models can enforce data integrity. The +:dependent+ option on associations allows models to automatically destroy child objects when the parent is destroyed. Like anything which operates at the application level these cannot guarantee referential integrity and so some people augment them with foreign key constraints. Although Active Record does not provide any tools for working directly with such features, the +execute+ method can be used to execute arbitrary SQL. There are also a number of plugins such as "foreign_key_migrations":http://github.com/harukizaemon/redhillonrails/tree/master/foreign_key_migrations/ which add foreign key support to Active Record (including support for dumping foreign keys in +db/schema.rb+). h3. Changelog -"Lighthouse ticket":http://rails.lighthouseapp.com/projects/16213-rails-guides/tickets/6 - * July 15, 2010: minor typos corrected by "Jaime Iniesta":http://jaimeiniesta.com * September 14, 2008: initial version by "Frederick Cheung":credits.html#fcheung |