HR@prod> create table test (id number,name varchar2(20));
Table created.
HR@prod> insert into test values(1,'abc');
1 row created.
HR@prod> insert into test values(2,'a_c');
1 row created.
HR@prod> insert into test values(3,'a%c');
1 row created.
HR@prod> select * from test;
ID NAME
---------- --------------------
1 abc
2 a_c
3 a%c
HR@prod> commit;
Commit complete.
HR@prod> select * from test where name like 'a%c';
ID NAME
---------- --------------------
1 abc
2 a_c
3 a%c
HR@prod> select * from test
2 where name like 'a\%c' escape '\';
ID NAME
---------- --------------------
3 a%c