with t1 as (
select  1  id from dual union all
select  2  id from dual union all
select  3  id from dual union all
select  4  id from dual)
,
t2 as (
select  1  fid,  23  val from dual union all
select  1  fid,  22  val from dual union all
select  2  fid,  28  val from dual union all
select  4  fid,  24  val from dual)

select t1.id, count( 1 ) from t1, t2 where t1.id=t2.fid group by t1.id