947 lines
30 KiB
Ruby
947 lines
30 KiB
Ruby
require "active_support/core_ext/class/attribute_accessors"
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require 'set'
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module ActiveRecord
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# Exception that can be raised to stop migrations from going backwards.
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class IrreversibleMigration < ActiveRecordError
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end
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class DuplicateMigrationVersionError < ActiveRecordError#:nodoc:
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def initialize(version)
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super("Multiple migrations have the version number #{version}")
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end
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end
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class DuplicateMigrationNameError < ActiveRecordError#:nodoc:
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def initialize(name)
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super("Multiple migrations have the name #{name}")
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end
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end
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class UnknownMigrationVersionError < ActiveRecordError #:nodoc:
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def initialize(version)
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super("No migration with version number #{version}")
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end
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end
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class IllegalMigrationNameError < ActiveRecordError#:nodoc:
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def initialize(name)
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super("Illegal name for migration file: #{name}\n\t(only lower case letters, numbers, and '_' allowed)")
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end
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end
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class PendingMigrationError < ActiveRecordError#:nodoc:
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def initialize
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super("Migrations are pending; run 'rake db:migrate RAILS_ENV=#{Rails.env}' to resolve this issue.")
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end
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end
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# = Active Record Migrations
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#
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# Migrations can manage the evolution of a schema used by several physical
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# databases. It's a solution to the common problem of adding a field to make
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# a new feature work in your local database, but being unsure of how to
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# push that change to other developers and to the production server. With
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# migrations, you can describe the transformations in self-contained classes
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# that can be checked into version control systems and executed against
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# another database that might be one, two, or five versions behind.
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#
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# Example of a simple migration:
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#
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# class AddSsl < ActiveRecord::Migration
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# def up
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# add_column :accounts, :ssl_enabled, :boolean, default: true
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# end
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#
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# def down
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# remove_column :accounts, :ssl_enabled
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# end
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# end
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#
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# This migration will add a boolean flag to the accounts table and remove it
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# if you're backing out of the migration. It shows how all migrations have
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# two methods +up+ and +down+ that describes the transformations
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# required to implement or remove the migration. These methods can consist
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# of both the migration specific methods like +add_column+ and +remove_column+,
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# but may also contain regular Ruby code for generating data needed for the
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# transformations.
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#
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# Example of a more complex migration that also needs to initialize data:
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#
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# class AddSystemSettings < ActiveRecord::Migration
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# def up
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# create_table :system_settings do |t|
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# t.string :name
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# t.string :label
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# t.text :value
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# t.string :type
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# t.integer :position
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# end
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#
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# SystemSetting.create name: 'notice',
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# label: 'Use notice?',
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# value: 1
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# end
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#
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# def down
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# drop_table :system_settings
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# end
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# end
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#
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# This migration first adds the +system_settings+ table, then creates the very
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# first row in it using the Active Record model that relies on the table. It
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# also uses the more advanced +create_table+ syntax where you can specify a
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# complete table schema in one block call.
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#
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# == Available transformations
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#
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# * <tt>create_table(name, options)</tt>: Creates a table called +name+ and
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# makes the table object available to a block that can then add columns to it,
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# following the same format as +add_column+. See example above. The options hash
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# is for fragments like "DEFAULT CHARSET=UTF-8" that are appended to the create
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# table definition.
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# * <tt>drop_table(name)</tt>: Drops the table called +name+.
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# * <tt>change_table(name, options)</tt>: Allows to make column alterations to
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# the table called +name+. It makes the table object availabe to a block that
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# can then add/remove columns, indexes or foreign keys to it.
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# * <tt>rename_table(old_name, new_name)</tt>: Renames the table called +old_name+
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# to +new_name+.
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# * <tt>add_column(table_name, column_name, type, options)</tt>: Adds a new column
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# to the table called +table_name+
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# named +column_name+ specified to be one of the following types:
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# <tt>:string</tt>, <tt>:text</tt>, <tt>:integer</tt>, <tt>:float</tt>,
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# <tt>:decimal</tt>, <tt>:datetime</tt>, <tt>:timestamp</tt>, <tt>:time</tt>,
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# <tt>:date</tt>, <tt>:binary</tt>, <tt>:boolean</tt>. A default value can be
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# specified by passing an +options+ hash like <tt>{ default: 11 }</tt>.
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# Other options include <tt>:limit</tt> and <tt>:null</tt> (e.g.
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# <tt>{ limit: 50, null: false }</tt>) -- see
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# ActiveRecord::ConnectionAdapters::TableDefinition#column for details.
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# * <tt>rename_column(table_name, column_name, new_column_name)</tt>: Renames
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# a column but keeps the type and content.
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# * <tt>change_column(table_name, column_name, type, options)</tt>: Changes
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# the column to a different type using the same parameters as add_column.
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# * <tt>remove_column(table_name, column_names)</tt>: Removes the column listed in
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# +column_names+ from the table called +table_name+.
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# * <tt>add_index(table_name, column_names, options)</tt>: Adds a new index
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# with the name of the column. Other options include
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# <tt>:name</tt>, <tt>:unique</tt> (e.g.
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# <tt>{ name: 'users_name_index', unique: true }</tt>) and <tt>:order</tt>
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# (e.g. <tt>{ order: { name: :desc } }</tt>).
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# * <tt>remove_index(table_name, column: column_name)</tt>: Removes the index
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# specified by +column_name+.
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# * <tt>remove_index(table_name, name: index_name)</tt>: Removes the index
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# specified by +index_name+.
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#
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# == Irreversible transformations
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#
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# Some transformations are destructive in a manner that cannot be reversed.
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# Migrations of that kind should raise an <tt>ActiveRecord::IrreversibleMigration</tt>
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# exception in their +down+ method.
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#
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# == Running migrations from within Rails
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#
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# The Rails package has several tools to help create and apply migrations.
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#
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# To generate a new migration, you can use
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# rails generate migration MyNewMigration
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#
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# where MyNewMigration is the name of your migration. The generator will
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# create an empty migration file <tt>timestamp_my_new_migration.rb</tt>
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# in the <tt>db/migrate/</tt> directory where <tt>timestamp</tt> is the
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# UTC formatted date and time that the migration was generated.
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#
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# You may then edit the <tt>up</tt> and <tt>down</tt> methods of
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# MyNewMigration.
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#
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# There is a special syntactic shortcut to generate migrations that add fields to a table.
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#
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# rails generate migration add_fieldname_to_tablename fieldname:string
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#
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# This will generate the file <tt>timestamp_add_fieldname_to_tablename</tt>, which will look like this:
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# class AddFieldnameToTablename < ActiveRecord::Migration
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# def up
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# add_column :tablenames, :fieldname, :string
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# end
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#
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# def down
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# remove_column :tablenames, :fieldname
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# end
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# end
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#
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# To run migrations against the currently configured database, use
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# <tt>rake db:migrate</tt>. This will update the database by running all of the
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# pending migrations, creating the <tt>schema_migrations</tt> table
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# (see "About the schema_migrations table" section below) if missing. It will also
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# invoke the db:schema:dump task, which will update your db/schema.rb file
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# to match the structure of your database.
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#
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# To roll the database back to a previous migration version, use
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# <tt>rake db:migrate VERSION=X</tt> where <tt>X</tt> is the version to which
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# you wish to downgrade. If any of the migrations throw an
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# <tt>ActiveRecord::IrreversibleMigration</tt> exception, that step will fail and you'll
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# have some manual work to do.
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#
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# == Database support
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#
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# Migrations are currently supported in MySQL, PostgreSQL, SQLite,
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# SQL Server, Sybase, and Oracle (all supported databases except DB2).
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#
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# == More examples
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#
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# Not all migrations change the schema. Some just fix the data:
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#
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# class RemoveEmptyTags < ActiveRecord::Migration
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# def up
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# Tag.all.each { |tag| tag.destroy if tag.pages.empty? }
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# end
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#
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# def down
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# # not much we can do to restore deleted data
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# raise ActiveRecord::IrreversibleMigration, "Can't recover the deleted tags"
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# end
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# end
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#
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# Others remove columns when they migrate up instead of down:
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#
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# class RemoveUnnecessaryItemAttributes < ActiveRecord::Migration
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# def up
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# remove_column :items, :incomplete_items_count
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# remove_column :items, :completed_items_count
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# end
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#
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# def down
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# add_column :items, :incomplete_items_count
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# add_column :items, :completed_items_count
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# end
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# end
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#
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# And sometimes you need to do something in SQL not abstracted directly by migrations:
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#
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# class MakeJoinUnique < ActiveRecord::Migration
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# def up
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# execute "ALTER TABLE `pages_linked_pages` ADD UNIQUE `page_id_linked_page_id` (`page_id`,`linked_page_id`)"
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# end
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#
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# def down
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# execute "ALTER TABLE `pages_linked_pages` DROP INDEX `page_id_linked_page_id`"
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# end
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# end
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#
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# == Using a model after changing its table
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#
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# Sometimes you'll want to add a column in a migration and populate it
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# immediately after. In that case, you'll need to make a call to
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# <tt>Base#reset_column_information</tt> in order to ensure that the model has the
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# latest column data from after the new column was added. Example:
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#
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# class AddPeopleSalary < ActiveRecord::Migration
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# def up
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# add_column :people, :salary, :integer
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# Person.reset_column_information
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# Person.all.each do |p|
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# p.update_attribute :salary, SalaryCalculator.compute(p)
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# end
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# end
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# end
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#
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# == Controlling verbosity
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#
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# By default, migrations will describe the actions they are taking, writing
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# them to the console as they happen, along with benchmarks describing how
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# long each step took.
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#
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# You can quiet them down by setting ActiveRecord::Migration.verbose = false.
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#
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# You can also insert your own messages and benchmarks by using the +say_with_time+
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# method:
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#
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# def up
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# ...
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# say_with_time "Updating salaries..." do
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# Person.all.each do |p|
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# p.update_attribute :salary, SalaryCalculator.compute(p)
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# end
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# end
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# ...
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# end
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#
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# The phrase "Updating salaries..." would then be printed, along with the
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# benchmark for the block when the block completes.
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#
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# == About the schema_migrations table
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#
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# Rails versions 2.0 and prior used to create a table called
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# <tt>schema_info</tt> when using migrations. This table contained the
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# version of the schema as of the last applied migration.
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#
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# Starting with Rails 2.1, the <tt>schema_info</tt> table is
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# (automatically) replaced by the <tt>schema_migrations</tt> table, which
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# contains the version numbers of all the migrations applied.
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#
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# As a result, it is now possible to add migration files that are numbered
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# lower than the current schema version: when migrating up, those
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# never-applied "interleaved" migrations will be automatically applied, and
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# when migrating down, never-applied "interleaved" migrations will be skipped.
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#
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# == Timestamped Migrations
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#
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# By default, Rails generates migrations that look like:
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#
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# 20080717013526_your_migration_name.rb
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#
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# The prefix is a generation timestamp (in UTC).
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#
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# If you'd prefer to use numeric prefixes, you can turn timestamped migrations
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# off by setting:
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#
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# config.active_record.timestamped_migrations = false
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#
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# In application.rb.
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#
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# == Reversible Migrations
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#
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# Starting with Rails 3.1, you will be able to define reversible migrations.
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# Reversible migrations are migrations that know how to go +down+ for you.
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# You simply supply the +up+ logic, and the Migration system will figure out
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# how to execute the down commands for you.
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#
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# To define a reversible migration, define the +change+ method in your
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# migration like this:
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#
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# class TenderloveMigration < ActiveRecord::Migration
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# def change
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# create_table(:horses) do |t|
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# t.column :content, :text
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# t.column :remind_at, :datetime
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# end
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# end
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# end
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#
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# This migration will create the horses table for you on the way up, and
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# automatically figure out how to drop the table on the way down.
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#
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# Some commands like +remove_column+ cannot be reversed. If you care to
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# define how to move up and down in these cases, you should define the +up+
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# and +down+ methods as before.
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#
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# If a command cannot be reversed, an
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# <tt>ActiveRecord::IrreversibleMigration</tt> exception will be raised when
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# the migration is moving down.
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#
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# For a list of commands that are reversible, please see
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# <tt>ActiveRecord::Migration::CommandRecorder</tt>.
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class Migration
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autoload :CommandRecorder, 'active_record/migration/command_recorder'
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# This class is used to verify that all migrations have been run before
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# loading a web page if config.active_record.migration_error is set to :page_load
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class CheckPending
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def initialize(app)
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@app = app
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end
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def call(env)
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ActiveRecord::Base.logger.quietly do
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ActiveRecord::Migration.check_pending!
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end
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@app.call(env)
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end
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end
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class << self
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attr_accessor :delegate # :nodoc:
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end
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def self.check_pending!
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raise ActiveRecord::PendingMigrationError if ActiveRecord::Migrator.needs_migration?
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end
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def self.method_missing(name, *args, &block) # :nodoc:
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(delegate || superclass.delegate).send(name, *args, &block)
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end
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def self.migrate(direction)
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new.migrate direction
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end
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cattr_accessor :verbose
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attr_accessor :name, :version
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def initialize(name = self.class.name, version = nil)
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@name = name
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@version = version
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@connection = nil
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end
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# instantiate the delegate object after initialize is defined
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self.verbose = true
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self.delegate = new
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# Reverses the migration commands for the given block and
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# the given migrations.
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#
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# The following migration will remove the table 'horses'
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# and create the table 'apples' on the way up, and the reverse
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# on the way down.
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#
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# class FixTLMigration < ActiveRecord::Migration
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# def change
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# revert do
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# create_table(:horses) do |t|
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# t.text :content
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# t.datetime :remind_at
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# end
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# end
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# create_table(:apples) do |t|
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# t.string :variety
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# end
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# end
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# end
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#
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# Or equivalently, if +TenderloveMigration+ is defined as in the
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# documentation for Migration:
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#
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# require_relative '2012121212_tenderlove_migration'
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#
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# class FixupTLMigration < ActiveRecord::Migration
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# def change
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# revert TenderloveMigration
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#
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# create_table(:apples) do |t|
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# t.string :variety
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# end
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# end
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# end
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#
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# This command can be nested.
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def revert(*migration_classes)
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run(*migration_classes.reverse, revert: true) unless migration_classes.empty?
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if block_given?
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if @connection.respond_to? :revert
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@connection.revert { yield }
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else
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recorder = CommandRecorder.new(@connection)
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@connection = recorder
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suppress_messages do
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@connection.revert { yield }
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end
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@connection = recorder.delegate
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recorder.commands.each do |cmd, args, block|
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send(cmd, *args, &block)
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end
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end
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end
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end
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def reverting?
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@connection.respond_to?(:reverting) && @connection.reverting
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end
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class ReversibleBlockHelper < Struct.new(:reverting)
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def up
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yield unless reverting
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end
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def down
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yield if reverting
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end
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end
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# Used to specify an operation that can be run in one direction or another.
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# Call the methods +up+ and +down+ of the yielded object to run a block
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# only in one given direction.
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# The whole block will be called in the right order within the migration.
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#
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# In the following example, the looping on users will always be done
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# when the three columns 'first_name', 'last_name' and 'full_name' exist,
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# even when migrating down:
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#
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# class SplitNameMigration < ActiveRecord::Migration
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# def change
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# add_column :users, :first_name, :string
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# add_column :users, :last_name, :string
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#
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# reversible do |dir|
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# User.reset_column_information
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# User.all.each do |u|
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# dir.up { u.first_name, u.last_name = u.full_name.split(' ') }
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# dir.down { u.full_name = "#{u.first_name} #{u.last_name}" }
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# u.save
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# end
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# end
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#
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# revert { add_column :users, :full_name, :string }
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# end
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# end
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def reversible
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helper = ReversibleBlockHelper.new(reverting?)
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execute_block{ yield helper }
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end
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# Runs the given migration classes.
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# Last argument can specify options:
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# - :direction (default is :up)
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# - :revert (default is false)
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def run(*migration_classes)
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opts = migration_classes.extract_options!
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dir = opts[:direction] || :up
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dir = (dir == :down ? :up : :down) if opts[:revert]
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if reverting?
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# If in revert and going :up, say, we want to execute :down without reverting, so
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revert { run(*migration_classes, direction: dir, revert: true) }
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else
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migration_classes.each do |migration_class|
|
|
migration_class.new.exec_migration(@connection, dir)
|
|
end
|
|
end
|
|
end
|
|
|
|
def up
|
|
self.class.delegate = self
|
|
return unless self.class.respond_to?(:up)
|
|
self.class.up
|
|
end
|
|
|
|
def down
|
|
self.class.delegate = self
|
|
return unless self.class.respond_to?(:down)
|
|
self.class.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
|
|
|
|
time = nil
|
|
ActiveRecord::Base.connection_pool.with_connection do |conn|
|
|
time = Benchmark.measure do
|
|
exec_migration(conn, direction)
|
|
end
|
|
end
|
|
|
|
case direction
|
|
when :up then announce "migrated (%.4fs)" % time.real; write
|
|
when :down then announce "reverted (%.4fs)" % time.real; write
|
|
end
|
|
end
|
|
|
|
def exec_migration(conn, direction)
|
|
@connection = conn
|
|
if respond_to?(:change)
|
|
if direction == :down
|
|
revert { change }
|
|
else
|
|
change
|
|
end
|
|
else
|
|
send(direction)
|
|
end
|
|
ensure
|
|
@connection = nil
|
|
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 connection
|
|
@connection || ActiveRecord::Base.connection
|
|
end
|
|
|
|
def method_missing(method, *arguments, &block)
|
|
arg_list = arguments.map{ |a| a.inspect } * ', '
|
|
|
|
say_with_time "#{method}(#{arg_list})" do
|
|
unless @connection.respond_to? :revert
|
|
unless arguments.empty? || method == :execute
|
|
arguments[0] = Migrator.proper_table_name(arguments.first)
|
|
arguments[1] = Migrator.proper_table_name(arguments.second) if method == :rename_table
|
|
end
|
|
end
|
|
return super unless connection.respond_to?(method)
|
|
connection.send(method, *arguments, &block)
|
|
end
|
|
end
|
|
|
|
def copy(destination, sources, options = {})
|
|
copied = []
|
|
|
|
FileUtils.mkdir_p(destination) unless File.exists?(destination)
|
|
|
|
destination_migrations = ActiveRecord::Migrator.migrations(destination)
|
|
last = destination_migrations.last
|
|
sources.each do |scope, path|
|
|
source_migrations = ActiveRecord::Migrator.migrations(path)
|
|
|
|
source_migrations.each do |migration|
|
|
source = File.read(migration.filename)
|
|
source = "# This migration comes from #{scope} (originally #{migration.version})\n#{source}"
|
|
|
|
if duplicate = destination_migrations.detect { |m| m.name == migration.name }
|
|
if options[:on_skip] && duplicate.scope != scope.to_s
|
|
options[:on_skip].call(scope, migration)
|
|
end
|
|
next
|
|
end
|
|
|
|
migration.version = next_migration_number(last ? last.version + 1 : 0).to_i
|
|
new_path = File.join(destination, "#{migration.version}_#{migration.name.underscore}.#{scope}.rb")
|
|
old_path, migration.filename = migration.filename, new_path
|
|
last = migration
|
|
|
|
File.open(migration.filename, "w") { |f| f.write source }
|
|
copied << migration
|
|
options[:on_copy].call(scope, migration, old_path) if options[:on_copy]
|
|
destination_migrations << migration
|
|
end
|
|
end
|
|
|
|
copied
|
|
end
|
|
|
|
def next_migration_number(number)
|
|
if ActiveRecord::Base.timestamped_migrations
|
|
[Time.now.utc.strftime("%Y%m%d%H%M%S"), "%.14d" % number].max
|
|
else
|
|
"%.3d" % number
|
|
end
|
|
end
|
|
|
|
private
|
|
def execute_block
|
|
if connection.respond_to? :execute_block
|
|
super # use normal delegation to record the block
|
|
else
|
|
yield
|
|
end
|
|
end
|
|
end
|
|
|
|
# MigrationProxy is used to defer loading of the actual migration classes
|
|
# until they are needed
|
|
class MigrationProxy < Struct.new(:name, :version, :filename, :scope)
|
|
|
|
def initialize(name, version, filename, scope)
|
|
super
|
|
@migration = nil
|
|
end
|
|
|
|
def basename
|
|
File.basename(filename)
|
|
end
|
|
|
|
delegate :migrate, :announce, :write, :to => :migration
|
|
|
|
private
|
|
|
|
def migration
|
|
@migration ||= load_migration
|
|
end
|
|
|
|
def load_migration
|
|
require(File.expand_path(filename))
|
|
name.constantize.new
|
|
end
|
|
|
|
end
|
|
|
|
class Migrator#:nodoc:
|
|
class << self
|
|
attr_writer :migrations_paths
|
|
alias :migrations_path= :migrations_paths=
|
|
|
|
def migrate(migrations_paths, target_version = nil, &block)
|
|
case
|
|
when target_version.nil?
|
|
up(migrations_paths, target_version, &block)
|
|
when current_version == 0 && target_version == 0
|
|
[]
|
|
when current_version > target_version
|
|
down(migrations_paths, target_version, &block)
|
|
else
|
|
up(migrations_paths, target_version, &block)
|
|
end
|
|
end
|
|
|
|
def rollback(migrations_paths, steps=1)
|
|
move(:down, migrations_paths, steps)
|
|
end
|
|
|
|
def forward(migrations_paths, steps=1)
|
|
move(:up, migrations_paths, steps)
|
|
end
|
|
|
|
def up(migrations_paths, target_version = nil)
|
|
migrations = migrations(migrations_paths)
|
|
migrations.select! { |m| yield m } if block_given?
|
|
|
|
self.new(:up, migrations, target_version).migrate
|
|
end
|
|
|
|
def down(migrations_paths, target_version = nil, &block)
|
|
migrations = migrations(migrations_paths)
|
|
migrations.select! { |m| yield m } if block_given?
|
|
|
|
self.new(:down, migrations, target_version).migrate
|
|
end
|
|
|
|
def run(direction, migrations_paths, target_version)
|
|
self.new(direction, migrations(migrations_paths), target_version).run
|
|
end
|
|
|
|
def open(migrations_paths)
|
|
self.new(:up, migrations(migrations_paths), nil)
|
|
end
|
|
|
|
def schema_migrations_table_name
|
|
SchemaMigration.table_name
|
|
end
|
|
|
|
def get_all_versions
|
|
SchemaMigration.all.map { |x| x.version.to_i }.sort
|
|
end
|
|
|
|
def current_version
|
|
sm_table = schema_migrations_table_name
|
|
if Base.connection.table_exists?(sm_table)
|
|
get_all_versions.max || 0
|
|
else
|
|
0
|
|
end
|
|
end
|
|
|
|
def needs_migration?
|
|
current_version < last_version
|
|
end
|
|
|
|
def last_version
|
|
migrations(migrations_paths).last.try(:version)||0
|
|
end
|
|
|
|
def proper_table_name(name)
|
|
# Use the Active Record objects own table_name, or pre/suffix from ActiveRecord::Base if name is a symbol/string
|
|
if name.respond_to? :table_name
|
|
name.table_name
|
|
else
|
|
"#{ActiveRecord::Base.table_name_prefix}#{name}#{ActiveRecord::Base.table_name_suffix}"
|
|
end
|
|
end
|
|
|
|
def migrations_paths
|
|
@migrations_paths ||= ['db/migrate']
|
|
# just to not break things if someone uses: migration_path = some_string
|
|
Array(@migrations_paths)
|
|
end
|
|
|
|
def migrations_path
|
|
migrations_paths.first
|
|
end
|
|
|
|
def migrations(paths)
|
|
paths = Array(paths)
|
|
|
|
files = Dir[*paths.map { |p| "#{p}/**/[0-9]*_*.rb" }]
|
|
|
|
migrations = files.map do |file|
|
|
version, name, scope = file.scan(/([0-9]+)_([_a-z0-9]*)\.?([_a-z0-9]*)?\.rb\z/).first
|
|
|
|
raise IllegalMigrationNameError.new(file) unless version
|
|
version = version.to_i
|
|
name = name.camelize
|
|
|
|
MigrationProxy.new(name, version, file, scope)
|
|
end
|
|
|
|
migrations.sort_by(&:version)
|
|
end
|
|
|
|
private
|
|
|
|
def move(direction, migrations_paths, steps)
|
|
migrator = self.new(direction, migrations(migrations_paths))
|
|
start_index = migrator.migrations.index(migrator.current_migration)
|
|
|
|
if start_index
|
|
finish = migrator.migrations[start_index + steps]
|
|
version = finish ? finish.version : 0
|
|
send(direction, migrations_paths, version)
|
|
end
|
|
end
|
|
end
|
|
|
|
def initialize(direction, migrations, target_version = nil)
|
|
raise StandardError.new("This database does not yet support migrations") unless Base.connection.supports_migrations?
|
|
|
|
@direction = direction
|
|
@target_version = target_version
|
|
@migrated_versions = nil
|
|
|
|
if Array(migrations).grep(String).empty?
|
|
@migrations = migrations
|
|
else
|
|
ActiveSupport::Deprecation.warn "instantiate this class with a list of migrations"
|
|
@migrations = self.class.migrations(migrations)
|
|
end
|
|
|
|
validate(@migrations)
|
|
|
|
ActiveRecord::SchemaMigration.create_table
|
|
end
|
|
|
|
def current_version
|
|
migrated.sort.last || 0
|
|
end
|
|
|
|
def current_migration
|
|
migrations.detect { |m| m.version == current_version }
|
|
end
|
|
alias :current :current_migration
|
|
|
|
def run
|
|
target = migrations.detect { |m| m.version == @target_version }
|
|
raise UnknownMigrationVersionError.new(@target_version) if target.nil?
|
|
unless (up? && migrated.include?(target.version.to_i)) || (down? && !migrated.include?(target.version.to_i))
|
|
target.migrate(@direction)
|
|
record_version_state_after_migrating(target.version)
|
|
end
|
|
end
|
|
|
|
def migrate
|
|
if !target && @target_version && @target_version > 0
|
|
raise UnknownMigrationVersionError.new(@target_version)
|
|
end
|
|
|
|
running = runnable
|
|
|
|
if block_given?
|
|
message = "block argument to migrate is deprecated, please filter migrations before constructing the migrator"
|
|
ActiveSupport::Deprecation.warn message
|
|
running.select! { |m| yield m }
|
|
end
|
|
|
|
running.each do |migration|
|
|
Base.logger.info "Migrating to #{migration.name} (#{migration.version})" if Base.logger
|
|
|
|
begin
|
|
ddl_transaction do
|
|
migration.migrate(@direction)
|
|
record_version_state_after_migrating(migration.version)
|
|
end
|
|
rescue => e
|
|
canceled_msg = Base.connection.supports_ddl_transactions? ? "this and " : ""
|
|
raise StandardError, "An error has occurred, #{canceled_msg}all later migrations canceled:\n\n#{e}", e.backtrace
|
|
end
|
|
end
|
|
end
|
|
|
|
def runnable
|
|
runnable = migrations[start..finish]
|
|
if up?
|
|
runnable.reject { |m| ran?(m) }
|
|
else
|
|
# skip the last migration if we're headed down, but not ALL the way down
|
|
runnable.pop if target
|
|
runnable.find_all { |m| ran?(m) }
|
|
end
|
|
end
|
|
|
|
def migrations
|
|
down? ? @migrations.reverse : @migrations.sort_by(&:version)
|
|
end
|
|
|
|
def pending_migrations
|
|
already_migrated = migrated
|
|
migrations.reject { |m| already_migrated.include?(m.version) }
|
|
end
|
|
|
|
def migrated
|
|
@migrated_versions ||= Set.new(self.class.get_all_versions)
|
|
end
|
|
|
|
private
|
|
def ran?(migration)
|
|
migrated.include?(migration.version.to_i)
|
|
end
|
|
|
|
def target
|
|
migrations.detect { |m| m.version == @target_version }
|
|
end
|
|
|
|
def finish
|
|
migrations.index(target) || migrations.size - 1
|
|
end
|
|
|
|
def start
|
|
up? ? 0 : (migrations.index(current) || 0)
|
|
end
|
|
|
|
def validate(migrations)
|
|
name ,= migrations.group_by(&:name).find { |_,v| v.length > 1 }
|
|
raise DuplicateMigrationNameError.new(name) if name
|
|
|
|
version ,= migrations.group_by(&:version).find { |_,v| v.length > 1 }
|
|
raise DuplicateMigrationVersionError.new(version) if version
|
|
end
|
|
|
|
def record_version_state_after_migrating(version)
|
|
if down?
|
|
migrated.delete(version)
|
|
ActiveRecord::SchemaMigration.where(:version => version.to_s).delete_all
|
|
else
|
|
migrated << version
|
|
ActiveRecord::SchemaMigration.create!(:version => version.to_s)
|
|
end
|
|
end
|
|
|
|
def up?
|
|
@direction == :up
|
|
end
|
|
|
|
def down?
|
|
@direction == :down
|
|
end
|
|
|
|
# Wrap the migration in a transaction only if supported by the adapter.
|
|
def ddl_transaction
|
|
if Base.connection.supports_ddl_transactions?
|
|
Base.transaction { yield }
|
|
else
|
|
yield
|
|
end
|
|
end
|
|
end
|
|
end
|