Is there an exchange format for ERD ?

Question

Is there a way to exchange ERD diagram from one tool to other as XMI exists for exchanging UML documents?

Answer 1

The closest thing I am aware of to this is the Common Warehouse Metamodel (CWM), which has support from some tool vendors. The official specification lives Here. Data modelling is a subset of this - it goes into mappings as well. As with specifications designed by committee it is comprehensive, verbose and probably quite difficult to implement.

A simpler method that will get you some of the way there is to export the schema as SQL, run it into a scratch database and reverse engineer it with the new tool. This will, however, tend to lose comments or any attached documentation. Depending on the tools, you may be able to bodge something together to rescue this.

For example, once I made a python script that would interpret the SQL output from Visio Enterprise Architect to generate MIF files for a data dictionary document. The output has the table and column docs in a format that is easy to parse and associate with column definitions. If you can programatically insert the comments into the repository of your destination tool you could use a similar technique for migration.