Check PDB/CDB

IN dbever

SELECT SYS_CONTEXT('USERENV', 'CON_NAME') AS container FROM dual;

In root

ALTER SESSION SET CONTAINER=CDB$ROOT;

SHOW CON_NAME;

Run on PDB on sqlplus

Docker exec and run

ALTER SESSION SET CONTAINER=ORCLPDB1;

sqlplus -L 'sys/StrongPass123@ORCLPDB1' as sysdba

Run on CDB using sqlplus

sqlplus / as sysdba