diff options
Diffstat (limited to 'activerecord/lib/active_record/migration.rb')
-rw-r--r-- | activerecord/lib/active_record/migration.rb | 66 |
1 files changed, 33 insertions, 33 deletions
diff --git a/activerecord/lib/active_record/migration.rb b/activerecord/lib/active_record/migration.rb index 7f26aa3f52..198f0a18cb 100644 --- a/activerecord/lib/active_record/migration.rb +++ b/activerecord/lib/active_record/migration.rb @@ -31,13 +31,13 @@ module ActiveRecord end # = Active Record Migrations - # - # Migrations can manage the evolution of a schema used by several physical + # + # Migrations can manage the evolution of a schema used by several physical # databases. It's a solution to the common problem of adding a field to make # a new feature work in your local database, but being unsure of how to - # push that change to other developers and to the production server. With + # push that change to other developers and to the production server. With # migrations, you can describe the transformations in self-contained classes - # that can be checked into version control systems and executed against + # that can be checked into version control systems and executed against # another database that might be one, two, or five versions behind. # # Example of a simple migration: @@ -52,12 +52,12 @@ module ActiveRecord # end # end # - # This migration will add a boolean flag to the accounts table and remove it - # if you're backing out of the migration. It shows how all migrations have - # two class methods +up+ and +down+ that describes the transformations + # This migration will add a boolean flag to the accounts table and remove it + # if you're backing out of the migration. It shows how all migrations have + # two class methods +up+ and +down+ that describes the transformations # required to implement or remove the migration. These methods can consist # of both the migration specific methods like add_column and remove_column, - # but may also contain regular Ruby code for generating data needed for the + # but may also contain regular Ruby code for generating data needed for the # transformations. # # Example of a more complex migration that also needs to initialize data: @@ -72,8 +72,8 @@ module ActiveRecord # t.integer :position # end # - # SystemSetting.create :name => "notice", - # :label => "Use notice?", + # SystemSetting.create :name => "notice", + # :label => "Use notice?", # :value => 1 # end # @@ -82,48 +82,48 @@ module ActiveRecord # end # end # - # This migration first adds the system_settings table, then creates the very + # This migration first adds the system_settings table, then creates the very # first row in it using the Active Record model that relies on the table. It - # also uses the more advanced create_table syntax where you can specify a + # also uses the more advanced create_table syntax where you can specify a # complete table schema in one block call. # # == Available transformations # - # * <tt>create_table(name, options)</tt> Creates a table called +name+ and + # * <tt>create_table(name, options)</tt> Creates a table called +name+ and # makes the table object available to a block that can then add columns to it, - # following the same format as add_column. See example above. The options hash - # is for fragments like "DEFAULT CHARSET=UTF-8" that are appended to the create + # following the same format as add_column. See example above. The options hash + # is for fragments like "DEFAULT CHARSET=UTF-8" that are appended to the create # table definition. # * <tt>drop_table(name)</tt>: Drops the table called +name+. - # * <tt>rename_table(old_name, new_name)</tt>: Renames the table called +old_name+ + # * <tt>rename_table(old_name, new_name)</tt>: Renames the table called +old_name+ # to +new_name+. - # * <tt>add_column(table_name, column_name, type, options)</tt>: Adds a new column + # * <tt>add_column(table_name, column_name, type, options)</tt>: Adds a new column # to the table called +table_name+ # named +column_name+ specified to be one of the following types: - # <tt>:string</tt>, <tt>:text</tt>, <tt>:integer</tt>, <tt>:float</tt>, + # <tt>:string</tt>, <tt>:text</tt>, <tt>:integer</tt>, <tt>:float</tt>, # <tt>:decimal</tt>, <tt>:datetime</tt>, <tt>:timestamp</tt>, <tt>:time</tt>, # <tt>:date</tt>, <tt>:binary</tt>, <tt>:boolean</tt>. A default value can be - # specified by passing an +options+ hash like <tt>{ :default => 11 }</tt>. - # Other options include <tt>:limit</tt> and <tt>:null</tt> (e.g. - # <tt>{ :limit => 50, :null => false }</tt>) -- see + # specified by passing an +options+ hash like <tt>{ :default => 11 }</tt>. + # Other options include <tt>:limit</tt> and <tt>:null</tt> (e.g. + # <tt>{ :limit => 50, :null => false }</tt>) -- see # ActiveRecord::ConnectionAdapters::TableDefinition#column for details. # * <tt>rename_column(table_name, column_name, new_column_name)</tt>: Renames # a column but keeps the type and content. - # * <tt>change_column(table_name, column_name, type, options)</tt>: Changes + # * <tt>change_column(table_name, column_name, type, options)</tt>: Changes # the column to a different type using the same parameters as add_column. - # * <tt>remove_column(table_name, column_name)</tt>: Removes the column named + # * <tt>remove_column(table_name, column_name)</tt>: Removes the column named # +column_name+ from the table called +table_name+. - # * <tt>add_index(table_name, column_names, options)</tt>: Adds a new index + # * <tt>add_index(table_name, column_names, options)</tt>: Adds a new index # with the name of the column. Other options include - # <tt>:name</tt> and <tt>:unique</tt> (e.g. + # <tt>:name</tt> and <tt>:unique</tt> (e.g. # <tt>{ :name => "users_name_index", :unique => true }</tt>). - # * <tt>remove_index(table_name, index_name)</tt>: Removes the index specified + # * <tt>remove_index(table_name, index_name)</tt>: Removes the index specified # by +index_name+. # # == Irreversible transformations # - # Some transformations are destructive in a manner that cannot be reversed. - # Migrations of that kind should raise an <tt>ActiveRecord::IrreversibleMigration</tt> + # Some transformations are destructive in a manner that cannot be reversed. + # Migrations of that kind should raise an <tt>ActiveRecord::IrreversibleMigration</tt> # exception in their +down+ method. # # == Running migrations from within Rails @@ -134,8 +134,8 @@ module ActiveRecord # rails generate migration MyNewMigration # # where MyNewMigration is the name of your migration. The generator will - # create an empty migration file <tt>timestamp_my_new_migration.rb</tt> - # in the <tt>db/migrate/</tt> directory where <tt>timestamp</tt> is the + # create an empty migration file <tt>timestamp_my_new_migration.rb</tt> + # in the <tt>db/migrate/</tt> directory where <tt>timestamp</tt> is the # UTC formatted date and time that the migration was generated. # # You may then edit the <tt>self.up</tt> and <tt>self.down</tt> methods of @@ -217,9 +217,9 @@ module ActiveRecord # # == Using a model after changing its table # - # Sometimes you'll want to add a column in a migration and populate it - # immediately after. In that case, you'll need to make a call to - # <tt>Base#reset_column_information</tt> in order to ensure that the model has the + # Sometimes you'll want to add a column in a migration and populate it + # immediately after. In that case, you'll need to make a call to + # <tt>Base#reset_column_information</tt> in order to ensure that the model has the # latest column data from after the new column was added. Example: # # class AddPeopleSalary < ActiveRecord::Migration |