I am a big fan of code generators and O/R Mappers to help generate a data access layer from a database. I have created my own code generator and ActiveRecord Framework as well as use many of the O/R Mappers for help with generating a data access layer for my applications. You can see a list of code generators and O/R Mappers at the following links:
Recently a code generator was added to CodePlex, called Generator Studio, which appears to be a customizable code generator that will generate classes from a database, very similiar to CodeSmith, CodeBreeze, or any template-based code generator. These types of code generators are always handy to have around for productivity reasons. Note that you can also use T4 Templates in Visual Studio 2008 as well:
Generator Studio is described as follows on CodePlex:
“A code generator application that makes use of the NVelocity template engine to generate code/scripts from a database. Initially developed to fill the gap left by the lack of Castle ActiveRecord generators/templates.
The source includes an initial template written in VTL for generating Castle ActiveRecord classes, including "PrimaryKey", "BelongsTo" and "HasMany" attributes.”
If you are looking for a free code generator to generate classes from a database, you may want to look at Generator Studio. I haven't personally looked at it, but you can download it here.
Other .NET Developer Tools.