Class: ActiveRecord::Migration::DefaultStrategy

Inherits:
ExecutionStrategy show all
Defined in:
activerecord/lib/active_record/migration/default_strategy.rb

Overview

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.

Method Summary

Methods inherited from ExecutionStrategy

#initialize

Constructor Details

This class inherits a constructor from ActiveRecord::Migration::ExecutionStrategy

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method) ⇒ Object (private) 



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# File 'activerecord/lib/active_record/migration/default_strategy.rb', line 54

def method_missing(method, ...)
  connection.send(method, ...)
end