Oracle 第一个答案。 SQL> DROP USER test CASCADE; DROP USER test CASCADE * ERROR at line 1: ORA-01940: cannot drop a user that is currently

第一个答案。

SQL> DROP USER test CASCADE;
DROP USER test CASCADE
*
ERROR at line 1:
ORA-01940: cannot drop a user that is currently connected

SQL> select sid,serial# from v$session where username = 'test';

no rows selected

SELECT s.sid, s.serial#, s.status, p.spid 
  FROM v$session s, v$process p 
 WHERE s.username = 'TEST' --<<<--
  AND p.addr(+) = s.paddr
 /

ALTER SYSTEM KILL SESSION '<SID>, <SERIAL>'
/

sqlplus  / as sysdba

sql>Shutdown immediate;

sql>startup restrict;

sql>drop user TEST cascade;

sql>Shutdown immediate;

sql>startup;

# A shell script to Drop a Database Schema, forcing off any Connected Sessions (for example, before an Import) 
# Warning! With great power comes great responsibility.
# It is often advisable to take an Export before Dropping a Schema

if [ "$1" = "" ] 
then
    echo "Which Schema?"
    read schema
else
    echo "Are you sure? (y/n)"
    read reply
    [ ! $reply = y ] && return 1
    schema=$1
fi

sqlplus / as sysdba <<EOF
set echo on
alter user $schema account lock;
-- Exterminate all sessions!
begin     
  for x in ( select sid, serial# from v\$session where username=upper('$schema') )
  loop  
   execute immediate ( 'alter system kill session '''|| x.Sid || ',' || x.Serial# || ''' immediate' );  
  end loop;  
  dbms_lock.sleep( seconds => 2 ); -- Prevent ORA-01940: cannot drop a user that is currently connected
end;
/
drop user $schema cascade;
quit
EOF

sql>Shutdown immediate;

sql>startup restrict;

sql>drop user TEST cascade;

select 'drop table ' || TABLE_NAME || ';'  from user_tables;

DECLARE
  v_user_exists NUMBER;
  user_name CONSTANT varchar2(20) := 'SCOTT';
BEGIN
  LOOP
    FOR c IN (SELECT s.sid, s.serial# FROM v$session s WHERE upper(s.username) = user_name)
    LOOP
      EXECUTE IMMEDIATE
        'alter system kill session ''' || c.sid || ',' || c.serial# || ''' IMMEDIATE';
    END LOOP;
    BEGIN
      EXECUTE IMMEDIATE 'drop user ' || user_name || ' cascade';
      EXCEPTION WHEN OTHERS THEN
      IF (SQLCODE = -1940) THEN
        NULL;
      ELSE
        RAISE;
      END IF;
    END;
    BEGIN
      SELECT COUNT(*) INTO v_user_exists FROM dba_users WHERE username = user_name;
      EXIT WHEN v_user_exists = 0;
    END;
  END LOOP;
END;
/

select * from gv$session where username = 'test';

alter system kill session 'sid, serial#, @inst_id' immediate;

SQL> ALTER SYSTEM ENABLE RESTRICTED SESSION;

SQL> DROP USER test CASCADE;

SQL> ALTER SYSTEM DISABLE RESTRICTED SESSION;