SchemaCrawler Database Diagramming

SchemaCrawler generates database diagrams using Graphviz in any of the output formats supported by Graphviz. SchemaCrawler is unique among database diagramming tools in that you do not need to know the table names or column names that you are interested in. All you need to know is what to search for, in the form of a regular expression. You can filter out tables, views, and columns based on regular expressions, using grep functionality. SchemaCrawler has powerful command-line options to match tables, and then find other tables related to the matched ones, whether they are parent or child tables. If your schema changes, you can simply regenerate the diagram, without having to know the exact changes that were made to the schema.

SchemaCrawler relies on Graphviz to generate diagrams. Install Graphviz first, and ensure that it is on the system PATH. If installing Graphviz is not an option for you, use the pure Java Graphviz library. Instructions are provided with the SchemaCrawler download, in the diagram example. Currently, the the pure Java Graphviz library is only able to generate PNG and SVG diagrams.

Then you can run SchemaCrawler with the correct command-line options - for example, -command=schema -outputformat=png -outputfile=graph.png

See the diagram example in the SchemaCrawler examples download. An example of a SchemaCrawler database diagram is below.

Database Diagram Options

SchemaCrawler offers several options to change what you see on the database diagram. Here are a few variations:

Additional Configuration

Diagram Options

You can decide whether foreign-key names, column ordinal numbers, and schema names are displayed by setting the following properties in the SchemaCrawler configuration file,


Table Row Counts

You can how table row counts on the database diagram, by setting the following properties in the SchemaCrawler configuration file,, and using -infolevel=maximum


Graphviz Command-line Options

You can provide additional Graphviz command-line options in one of three ways:

SchemaCrawler does not set the dpi, or resolution of generated graphs. A useful Graphviz command-line option to set is -Gdpi=300. In the SchemaCrawler configuration file,, this would look like: ​


Embedded Diagrams

SchemaCrawler can generate SVG diagrams embedded in HTML output. To generate this format, run SchemaCrawler with an -outputformat=htmlx command-line argument. Please edit the SchemaCrawler configuration file,, and comment out or delete the line schemacrawler.graph.graphviz_opts=-Gdpi=300.


SchemaCrawler Diagrams in Use

Schemacrawler database diagrams in use at the Scrum meeting at the Software Development Departement of La Ville de Nouméa. Photograph courtesy of Adrien Sales.

Schemacrawler database diagrams in use