Creating Dia Data Diagrams from Database Schema

As I stated in earlier posts, you can use dbscript to generate PNG Data Diagrams (MS SQL Server, Oracle, PostgreSQL).

The generated PNG files are intended to give you an overview of the data model. The great drawback is that the information is graphical only, as it contains no information on the original data.

Upcoming version 0.99 will also include the capability to generate Dia files representing a database schema. Dia is an open-source diagram creation program which runs on Windows and Linux.

The advantages of generating in Dia format are that it allows users / developers to modify the generated diagrams, and that general Dia functionality can be used as stated on their website:

[It] can export diagrams to a number of formats, including EPS, SVG, XFIG, WMF and PNG, and can print diagrams (including ones that span multiple pages).

There is one minor issue in generating and opening Dia files: since Dia automatically sizes Table shapes according to their contents, it is not possible to predict what the table shape size will turn out to be (see FAQ). Thus when you open a generated Dia file for the first time, the foreign key connectors will look disconnected from the tables, even though they are not (in the data).

You need to manually enforce connector layout following these steps:

• Select All (Ctrl-A)
• Move selected objects (Cursor-Left, then Cursor-Right)

which will layout the foreign key connectors as expected.

Visit the gallery to view PNG images generated by Dia from diagrams created by dbscript.

Download Dia files with database models of

• MS AdventureWorks 2005
• OpenNMS
• Oracle Demo Schema

You need to install Dia to view the contents of these files.