I can't find the active record documenation page that has a list of all the data types.
Can someone help me out?
If you're talking about the types for migrations, e.g. string, integer, datetime, etc, then you want ActiveRecord::ConnectionAdapters::TableDefinition, the column method. (Rails 5 edit: see also connection.add_column.)
As of this update, the standard types are:
:primary_key:string:text:integer:bigint:float:decimal:numeric:datetime:time:date:binary:booleanThe implementation of :decimal is different with each database, so I'd avoid it if possible. You may use a type not in this list as long as it is supported by your database (for example, :polygon in MySQL), but this will not be database agnostic and should also be avoided.