create table test
(
name varchar2(100));
insert into test values('abc.def');
insert into test values('def.ghf.klh');
insert into test values ('abc.def@gmail');
commit;
select name from btpeople where REGEXP_LIKE(name, '^[a-zA-Z][.a-zA-Z]+$');
output:-
abc.def
def.ghf.klh
But i want result only :-
abc.def
(that is alphabet then one dot and then alphabet)