Diffstat (limited to 'vendor/rails/activerecord/lib/active_record/migration.rb') (more/less context) (ignore whitespace changes)
| -rw-r--r-- | vendor/rails/activerecord/lib/active_record/migration.rb | 417 |
1 files changed, 0 insertions, 417 deletions
diff --git a/vendor/rails/activerecord/lib/active_record/migration.rb b/vendor/rails/activerecord/lib/active_record/migration.rb deleted file mode 100644 index cbdef1d..0000000 --- a/vendor/rails/activerecord/lib/active_record/migration.rb +++ b/dev/null @@ -1,417 +0,0 @@ -module ActiveRecord - class IrreversibleMigration < ActiveRecordError#:nodoc: - end - - class DuplicateMigrationVersionError < ActiveRecordError#:nodoc: - def initialize(version) - super("Multiple migrations have the version number #{version}") - end - end - - class IllegalMigrationNameError < ActiveRecordError#:nodoc: - def initialize(name) - super("Illegal name for migration file: #{name}\n\t(only lower case letters, numbers, and '_' allowed)") - end - end - - # 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 migrations, you can describe the transformations - # in self-contained classes 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: - # - # class AddSsl < ActiveRecord::Migration - # def self.up - # add_column :accounts, :ssl_enabled, :boolean, :default => 1 - # end - # - # def self.down - # remove_column :accounts, :ssl_enabled - # 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 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 transformations. - # - # Example of a more complex migration that also needs to initialize data: - # - # class AddSystemSettings < ActiveRecord::Migration - # def self.up - # create_table :system_settings do |t| - # t.string :name - # t.string :label - # t.text :value - # t.string :type - # t.integer :position - # end - # - # SystemSetting.create :name => "notice", :label => "Use notice?", :value => 1 - # end - # - # def self.down - # drop_table :system_settings - # end - # end - # - # 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 complete table schema - # in one block call. - # - # == Available transformations - # - # * <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 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+ to +new_name+. - # * <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: - # :string, :text, :integer, :float, :decimal, :datetime, :timestamp, :time, - # :date, :binary, :boolean. A default value can be specified by passing an - # +options+ hash like { :default => 11 }. Other options include :limit and :null (e.g. { :limit => 50, :null => false }) - # -- 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 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 +column_name+ from the table called +table_name+. - # * <tt>add_index(table_name, column_names, options)</tt>: Adds a new index with the name of the column. Other options include - # :name and :unique (e.g. { :name => "users_name_index", :unique => true }). - # * <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> exception in their +down+ method. - # - # == Running migrations from within Rails - # - # The Rails package has several tools to help create and apply migrations. - # - # To generate a new migration, use <tt>script/generate migration MyNewMigration</tt> - # where MyNewMigration is the name of your migration. The generator will - # create a file <tt>nnn_my_new_migration.rb</tt> in the <tt>db/migrate/</tt> - # directory where <tt>nnn</tt> is the next largest migration number. - # You may then edit the <tt>self.up</tt> and <tt>self.down</tt> methods of - # MyNewMigration. - # - # To run migrations against the currently configured database, use - # <tt>rake db:migrate</tt>. This will update the database by running all of the - # pending migrations, creating the <tt>schema_info</tt> table if missing. - # - # To roll the database back to a previous migration version, use - # <tt>rake db:migrate VERSION=X</tt> where <tt>X</tt> is the version to which - # you wish to downgrade. If any of the migrations throw an - # <tt>ActiveRecord::IrreversibleMigration</tt> exception, that step will fail and you'll - # have some manual work to do. - # - # == Database support - # - # Migrations are currently supported in MySQL, PostgreSQL, SQLite, - # SQL Server, Sybase, and Oracle (all supported databases except DB2). - # - # == More examples - # - # Not all migrations change the schema. Some just fix the data: - # - # class RemoveEmptyTags < ActiveRecord::Migration - # def self.up - # Tag.find(:all).each { |tag| tag.destroy if tag.pages.empty? } - # end - # - # def self.down - # # not much we can do to restore deleted data - # raise ActiveRecord::IrreversibleMigration, "Can't recover the deleted tags" - # end - # end - # - # Others remove columns when they migrate up instead of down: - # - # class RemoveUnnecessaryItemAttributes < ActiveRecord::Migration - # def self.up - # remove_column :items, :incomplete_items_count - # remove_column :items, :completed_items_count - # end - # - # def self.down - # add_column :items, :incomplete_items_count - # add_column :items, :completed_items_count - # end - # end - # - # And sometimes you need to do something in SQL not abstracted directly by migrations: - # - # class MakeJoinUnique < ActiveRecord::Migration - # def self.up - # execute "ALTER TABLE `pages_linked_pages` ADD UNIQUE `page_id_linked_page_id` (`page_id`,`linked_page_id`)" - # end - # - # def self.down - # execute "ALTER TABLE `pages_linked_pages` DROP INDEX `page_id_linked_page_id`" - # end - # end - # - # == 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 Base#reset_column_information in order to ensure that the model has the latest column data from - # after the new column was added. Example: - # - # class AddPeopleSalary < ActiveRecord::Migration - # def self.up - # add_column :people, :salary, :integer - # Person.reset_column_information - # Person.find(:all).each do |p| - # p.update_attribute :salary, SalaryCalculator.compute(p) - # end - # end - # end - # - # == Controlling verbosity - # - # By default, migrations will describe the actions they are taking, writing - # them to the console as they happen, along with benchmarks describing how - # long each step took. - # - # You can quiet them down by setting ActiveRecord::Migration.verbose = false. - # - # You can also insert your own messages and benchmarks by using the #say_with_time - # method: - # - # def self.up - # ... - # say_with_time "Updating salaries..." do - # Person.find(:all).each do |p| - # p.update_attribute :salary, SalaryCalculator.compute(p) - # end - # end - # ... - # end - # - # The phrase "Updating salaries..." would then be printed, along with the - # benchmark for the block when the block completes. - class Migration - @@verbose = true - cattr_accessor :verbose - - class << self - def up_with_benchmarks #:nodoc: - migrate(:up) - end - - def down_with_benchmarks #:nodoc: - migrate(:down) - end - - # Execute this migration in the named direction - def migrate(direction) - return unless respond_to?(direction) - - case direction - when :up then announce "migrating" - when :down then announce "reverting" - end - - result = nil - time = Benchmark.measure { result = send("#{direction}_without_benchmarks") } - - case direction - when :up then announce "migrated (%.4fs)" % time.real; write - when :down then announce "reverted (%.4fs)" % time.real; write - end - - result - end - - # Because the method added may do an alias_method, it can be invoked - # recursively. We use @ignore_new_methods as a guard to indicate whether - # it is safe for the call to proceed. - def singleton_method_added(sym) #:nodoc: - return if @ignore_new_methods - - begin - @ignore_new_methods = true - - case sym - when :up, :down - klass = (class << self; self; end) - klass.send(:alias_method_chain, sym, "benchmarks") - end - ensure - @ignore_new_methods = false - end - end - - def write(text="") - puts(text) if verbose - end - - def announce(message) - text = "#{@version} #{name}: #{message}" - length = [0, 75 - text.length].max - write "== %s %s" % [text, "=" * length] - end - - def say(message, subitem=false) - write "#{subitem ? " ->" : "--"} #{message}" - end - - def say_with_time(message) - say(message) - result = nil - time = Benchmark.measure { result = yield } - say "%.4fs" % time.real, :subitem - say("#{result} rows", :subitem) if result.is_a?(Integer) - result - end - - def suppress_messages - save, self.verbose = verbose, false - yield - ensure - self.verbose = save - end - - def method_missing(method, *arguments, &block) - arg_list = arguments.map(&:inspect) * ', ' - - say_with_time "#{method}(#{arg_list})" do - unless arguments.empty? || method == :execute - arguments[0] = Migrator.proper_table_name(arguments.first) - end - ActiveRecord::Base.connection.send(method, *arguments, &block) - end - end - end - end - - class Migrator#:nodoc: - class << self - def migrate(migrations_path, target_version = nil) - Base.connection.initialize_schema_information - - case - when target_version.nil?, current_version < target_version - up(migrations_path, target_version) - when current_version > target_version - down(migrations_path, target_version) - when current_version == target_version - return # You're on the right version - end - end - - def up(migrations_path, target_version = nil) - self.new(:up, migrations_path, target_version).migrate - end - - def down(migrations_path, target_version = nil) - self.new(:down, migrations_path, target_version).migrate - end - - def schema_info_table_name - Base.table_name_prefix + "schema_info" + Base.table_name_suffix - end - - def current_version - Base.connection.select_value("SELECT version FROM #{schema_info_table_name}").to_i - end - - def proper_table_name(name) - # Use the ActiveRecord objects own table_name, or pre/suffix from ActiveRecord::Base if name is a symbol/string - name.table_name rescue "#{ActiveRecord::Base.table_name_prefix}#{name}#{ActiveRecord::Base.table_name_suffix}" - end - end - - def initialize(direction, migrations_path, target_version = nil) - raise StandardError.new("This database does not yet support migrations") unless Base.connection.supports_migrations? - @direction, @migrations_path, @target_version = direction, migrations_path, target_version - Base.connection.initialize_schema_information - end - - def current_version - self.class.current_version - end - - def migrate - migration_classes.each do |migration_class| - if reached_target_version?(migration_class.version) - Base.logger.info("Reached target version: #{@target_version}") - break - end - - next if irrelevant_migration?(migration_class.version) - - Base.logger.info "Migrating to #{migration_class} (#{migration_class.version})" - migration_class.migrate(@direction) - set_schema_version(migration_class.version) - end - end - - def pending_migrations - migration_classes.select { |m| m.version > current_version } - end - - private - def migration_classes - migrations = migration_files.inject([]) do |migrations, migration_file| - load(migration_file) - version, name = migration_version_and_name(migration_file) - assert_unique_migration_version(migrations, version.to_i) - migrations << migration_class(name, version.to_i) - end - - sorted = migrations.sort_by { |m| m.version } - down? ? sorted.reverse : sorted - end - - def assert_unique_migration_version(migrations, version) - if !migrations.empty? && migrations.find { |m| m.version == version } - raise DuplicateMigrationVersionError.new(version) - end - end - - def migration_files - files = Dir["#{@migrations_path}/[0-9]*_*.rb"].sort_by do |f| - m = migration_version_and_name(f) - raise IllegalMigrationNameError.new(f) unless m - m.first.to_i - end - down? ? files.reverse : files - end - - def migration_class(migration_name, version) - klass = migration_name.camelize.constantize - class << klass; attr_accessor :version end - klass.version = version - klass - end - - def migration_version_and_name(migration_file) - return *migration_file.scan(/([0-9]+)_([_a-z0-9]*).rb/).first - end - - def set_schema_version(version) - Base.connection.update("UPDATE #{self.class.schema_info_table_name} SET version = #{down? ? version.to_i - 1 : version.to_i}") - end - - def up? - @direction == :up - end - - def down? - @direction == :down - end - - def reached_target_version?(version) - return false if @target_version == nil - (up? && version.to_i - 1 >= @target_version) || (down? && version.to_i <= @target_version) - end - - def irrelevant_migration?(version) - (up? && version.to_i <= current_version) || (down? && version.to_i > current_version) - end - end -end |