The Mogwai ERDesigner is a entity relation modeling tool such as ERWin and co. The only difference is that it is Open Source and does not cost anything. It was designed to make database modeling as easy as it can be and to support the developer in the whole development process, from database design to schema and code generation. This tool was also designed to support a flexible plug in architecture, to extend the system simply by installing a new plug in. This way, everybody can implement new features and tools to make ERDesigner fit the requirements.
ERDesigner NG
* is based on Java and can be run on Windows and Unix systems
* has a powerfull WYSIWYG for physical database design
* handles tables, relations, indexes and comments
* supports subject areas
* supports MySQL, Oracle, Microsoft SQLServer and Postgres
* creates the SQL DDL statements for schema creation
* has an integrated schema version control system
* can generate schema migration scripts for every change
* stores the database definition as XML files for further processing
* can export the database schema as GIF, BMP, JPEG or SVG files
* has an integrated reverse engineering module for existing schemas
* it is based on GPL license
* support is available by authors and newsgroups
Do you hate starting on a new project and having to try to figure out someone else's idea of a database? Or are you in QA and the developers expect you to understand all the relationships in their schema? If so then this tool's for you.
SchemaSpy is a Java-based tool (requires Java 1.4 or higher) that analyzes the metadata of a schema in a database and generates a visual representation of it in a browser-displayable format. It lets you click through the hierarchy of database tables via child and parent table relationships. The browsing through relationships can occur though HTML links and/or though the graphical representation of the relationships. It's also designed to help resolve the obtuse errors that a database sometimes gives related to failures due to constraints.