Default Strategy¶ ↑

DefaultStrategy is the default execution strategy for migrations. It delegates all method calls directly to the connection adapter, which is the standard behavior for executing migration commands.

This class is the recommended base class for custom migration strategies. By inheriting from DefaultStrategy, you can override specific methods while retaining the default behavior for all other migration operations.

Example: Creating a Custom Strategy¶ ↑

class AuditingStrategy < ActiveRecord::Migration::DefaultStrategy
  def create_table(table_name, **options)
    Rails.logger.info "Creating table: #{table_name}"
    super
  end

  def drop_table(table_name, **options)
    Rails.logger.warn "Dropping table: #{table_name}"
    super
  end
end

# Apply globally
config.active_record.migration_strategy = AuditingStrategy

# Or apply to a specific adapter
ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.migration_strategy = AuditingStrategy

Available Methods¶ ↑

DefaultStrategy responds to all methods available on the connection adapter, including but not limited to:

• create_table

• drop_table

• add_column

• remove_column

• add_index

• remove_index

• add_foreign_key

• remove_foreign_key

• execute

See ActiveRecord::ConnectionAdapters::SchemaStatements for the complete list of available schema modification methods.