SQL>
SQL> CREATE TABLE emp (
2 id NUMBER PRIMARY KEY,
3 fname VARCHAR2(50),
4 lname VARCHAR2(50)
5 );
Table created.
SQL>
SQL> INSERT INTO emp (id, fname, lname)VALUES (1, 'A', 'B');
1 row created.
SQL> INSERT INTO emp (id, fname, lname)VALUES (2, 'C', 'D');
1 row created.
SQL> INSERT INTO emp (id, fname, lname)VALUES (3, 'E', 'F');
1 row created.
SQL> INSERT INTO emp (id, fname, lname)VALUES (4, 'G', 'H');
1 row created.
SQL> INSERT INTO emp (id, fname, lname)VALUES (5, 'G', 'Z');
1 row created.
SQL>
SQL> UPDATE emp
2 SET fname = 'Ronald'
3 WHERE id = 44;
0 rows updated.
SQL>
SQL> SELECT d.session_id sid, d.lock_type, d.mode_requested,
2 d.mode_held, d.blocking_others
3 FROM dba_locks d, v$session v
4 WHERE v.username = 'PLSQL'
5 AND d.session_id = v.sid;
no rows selected
SQL>
SQL> drop table emp;
Table dropped.