Why don't CAS users show up in users_field_data? I have a simple multisite setup in Drupal 8. I installed the CAS module and verified that at least one user logged in successfully using our university's CAS server. 

I can see the user at /admin/people, but I cannot see his entry in the database. I looked in the tables users, users_data, and users_field_data, and all I can see is the admin user (me). 

Where are the users located in the database? 

I need to know for a custom module I am developing. FWIW I do have "Auto Register Users" enabled in the module configuration.
For D8, CAS requires External Authentication module. 


External Authentication maintains a db table called authmap.
CAS maintains a table named cas_login_data.


I suspect the data you're looking for is in one of those tables.