You have generated the demo data for the SQL Tutorial.
Log on to the demo database instance DEMODB as user MONA.
Create referential constraints. Proceed as described in SQL Tutorial, Foreign Key Dependencies Between Tables.
You can use the system table FOREIGNKEYS to determine the following database information, among other things:
? All referential constraints in which the RESERVATION table is the referencing table
SELECT fkeyname, tablename
WHERE tablename = 'RESERVATION'
? All referential constraints generated with the DELETE CASCADE rule
SELECT schemaname, fkeyname
WHERE rule = 'DELETE CASCADE'
Columns in referential constraints: see FOREIGNKEYCOLUMNS