Sometimes, just occasionally, you find yourself as a DBA on a site where, for some strange and unknown reason, you don’t have an Entity Relationship Diagram (ERD) for the database that you are working on. You could use a tool such as Toad, or SQL*Plus (or even, SQL Developer – if you must) to generate a list of referential integrity constraints. There has to be a better way.
This is a companion discussion topic for the original entry at https://blog.toadworld.com/generate-entity-relationship-diagrams-from-a-sql-script