How to generate an entity-relationship (ER) diagram using Oracle SQL Developer

Create a diagram for existing database schema or its subset as follows:

1. Click File → Data Modeler → Import → Data Dictionary.
2. Select a DB connection (add one if none).
3. Click Next.
4. Check one or more schema names.
5. Click Next.
6. Check one or more objects to import.
7. Click Next.
8. Click Finish.

The ERD is displayed.

Export the diagram as follows:

1. Click File → Data Modeler → Print Diagram → To Image File.
2. Browse to and select the export file location.
3. Click Save.

The diagram is exported. To export in a vector format, use To PDF File, instead. This allows for simplified editing using Inkscape (or other vector image editor).

These instructions may work for SQL Developer 3.2.09.23 to 4.1.3.20.