As I can't find any ER diagram feature built in with Apex, I want to create one with the SQL statements I executed in order to set up the tables in my Apex Workbench.
I found schemaSpy, which is capable of generating diagrams from many database architectures, but it can't connect to Apex. (AFAIK)
Most of the other tools I found are doing the opposite of what I want - they let you design your scheme in a nice user interface and generate the according SQL statements afterwards.
As it was mentioned in the comments (and in other questions on stackexchange), it's possible to connect to Oracle Apex through ODBC, generating a diagram with some tools, i.e. Microsoft Visio.
Maybe I have to do it this way, but I was curious, if it's possible even without an existing database scheme; just SQL.
Is there a free (better: open source) tool which analyzes given CREATE TABLE-statements, including foreign keys, to an entity relationship diagram?