diff --git a/railties/guides/source/migrations.textile b/railties/guides/source/migrations.textile index 4f52e3ee8d..e6401a4bb7 100644 --- a/railties/guides/source/migrations.textile +++ b/railties/guides/source/migrations.textile @@ -109,8 +109,15 @@ them). Active Record provides methods that perform common data definition tasks in a database independent way (you'll read about them in detail later): -* +create_table+ +change_table+ +drop_table+ +add_column+ +change_column+ -* +rename_column+ +remove_column+ +add_index+ +remove_index+ +* +add_column+ +* +add_index+ +* +change_column+ +* +change_table+ +* +create_table+ +* +drop_table+ +* +remove_column+ +* +remove_index+ +* +rename_column+ If you need to perform tasks specific to your database (for example create a "foreign key":#active-record-and-referential-integrity constraint) then the @@ -184,10 +191,20 @@ development machine) is relatively harmless. h4. Supported Types -Active Record supports the following types: +Active Record supports the following database column types: -* +:primary_key+ +:string+ +:text+ +:integer+ +:float+ +:decimal+ +:datetime+ -* +:timestamp+ +:time+ +:date+ +:binary+ +:boolean+ +* +:binary+ +* +:boolean+ +* +:date+ +* +:datetime+ +* +:decimal+ +* +:float+ +* +:integer+ +* +:primary_key+ +* +:string+ +* +:text+ +* +:time+ +* +:timestamp+ These will be mapped onto an appropriate underlying database type. For example, with MySQL the type +:string+ is mapped to +VARCHAR(255)+. You can create @@ -455,8 +472,14 @@ The +change+ method removes the need to write both +up+ and +down+ methods in those cases that Rails know how to revert the changes automatically. Currently, the +change+ method supports only these migration definitions: -* +add_column+ +add_index+ +add_timestamps+ +create_table+ +remove_timestamps+ -* +rename_column+ +rename_index+ +rename_table+ +* +add_column+ +* +add_index+ +* +add_timestamps+ +* +create_table+ +* +remove_timestamps+ +* +rename_column+ +* +rename_index+ +* +rename_table+ If you're going to use other methods, you'll have to write the +up+ and +down+ methods normally.