How to drop oracle users

Before dropping a user, it is recommended to first Lock the user.

Here below  is the SQL statement to drop a user:

SQL>  drop user <user>;

If user owns database objects the above command will not work and use CASCADE clause for users that have database objects.

SQL>  drop user <user> CASCADE

Example:

SQL> conn sys/orcl@to_primary as sysdba
Connected.
SQL> drop user mereba;
drop user mereba
*
ERROR at line 1:
ORA-01922: CASCADE must be specified to drop 'MEREBA'

SQL> drop user mereba cascade;
 User dropped.
SQL>