Rails 3 datatypes?

Here are all the Rails3 (ActiveRecord migration) datatypes:

:binary
:boolean
:date
:datetime
:decimal
:float
:integer
:primary_key
:references
:string
:text
:time
:timestamp

Source

It is important to know not only the types but the mapping of these types to the database types, too:

For, example, note that in MS SQL Server we are using:

1. the old "datetime" instead "datetime2"
2. decimal with its default precision
3. text and varchar instead nvarchar
4. int (not possible to use tiny int/small int/big int)
5. image instead BLOB