Does exist ORM / Framework that converts data automatically when I want to change column datatype in table?

Assume that I have existing database with existing data.

Is there any framework / ORM that generates data conversion SQL scripts when I need change column datatype? Of course there is problem with conversions like

• float to int
• string to int

, but I would like to have such default functionality that automatically converts data from

• int to float
• int to string.

Do I have always to write data SQL data conversion scripts in both cases?

In the .Net world I've had very good experience with LLBLGen Pro. It supports the generation of DDL scripts to migrate the underlying database to the updated entity definitions. Here is quick start guide that shows the overview of how this works, and here is documentation section for Model-First design process

You can either use it with its own runtime framework, or simply as a design tool for Entity Framework, NHibernate, or Linq to SQL.