Toad Data Modeler

Toad Data Modeler is a database design tool allowing users to visually create, maintain and document new or exsiting database systems.

[edit] Features

With Toad Data Modeler you can:

Visually create database structures (logical and physical entity-relationship diagrams - ERD)
Create ERD for various database systems (Oracle, MS SQL, DB2 MySQL etc.)
Reverse engineer already existing database structures and see the existing database structure in form of a diagram
Add logical data to ER diagrams and describe existing database structures better
Verify ERD (model) and get a list of Errors, Warnings and Hints
Automatically generate SQL code for selected target database
Generate detailed documentation in HTML or RTF format
Synchronize models with physically existing database (using Alter Script Generation and Model Merge features)
Keep track of changes using internal Version Manager
Create and maintain a list of tasks related to your model or particular part of a model using To-Do list feature.
Customize the product accordingly to your requirements (including customization of forms)
Affect objects in ERD via internal scripting (user-defined batch rename scripts etc.)