Connected TO Oracle DATABASE 10g Enterprise Edition Release 10.1.0.3.0
Connected AS msq

SQL>
SQL>
SQL> CREATE TABLE test_mirko (colA VARCHAR(20), colB VARCHAR(20));

TABLE created

SQL> INSERT INTO test_mirko VALUES ('test', 'Test');

1 ROW inserted

SQL> INSERT INTO test_mirko VALUES ('test', 'test');

1 ROW inserted

SQL> INSERT INTO test_mirko VALUES ('test', 'testAAA');

1 ROW inserted

SQL> INSERT INTO test_mirko VALUES ('test', 'tesT');

1 ROW inserted

SQL> commit;

Commit complete

SQL> SELECT * FROM test_mirko WHERE colA = colB;

COLA                 COLB
-------------------- --------------------
test                 test

SQL> SELECT * FROM test_mirko WHERE colA LIKE colB;

COLA                 COLB
-------------------- --------------------
test                 test

SQL>