mysql> create table a (id int,fid int ,name varchar(10));
Query OK, 0 rows affected (0.10 sec)

mysql>insertintoavalue(1,1,'a');
QueryOK,1rowaffected(0.04sec)

mysql>insertintoavalue(2,1,'b');
QueryOK,1rowaffected(0.01sec)

mysql>insertintoavalue(3,1,'c');
QueryOK,1rowaffected(0.01sec)

mysql>insertintoavalue(4,2,'d');
QueryOK,1rowaffected(0.02sec)

mysql>insertintoavalue(5,2,'e');
QueryOK,1rowaffected(0.01sec)

mysql>insertintoavalue(6,2,'f');
QueryOK,1rowaffected(0.00sec)

mysql>select*froma
->;
+------+------+------+
|id|fid|name|
+------+------+------+
|1|1|a|
|2|1|b|
|3|1|c|
|4|2|d|
|5|2|e|
|6|2|f|
+------+------+------+
6rowsinset(0.00sec)

mysql> select * from a where 2>( select count(*) from a b where a.fid=b.fid and a.id<b.id )order by fid ;
+------+------+------+
| id| fid | name |
+------+------+------+
|2 |1 | b|
|3 |1 | c|
|5 |2 | e|
|6 |2 | f|
+------+------+------+
4 rows in set (0.00 sec)


mysql> select * from a where 2>( select count(*) from a b where a.fid=b.fid and a.id>b.id )order by fid ;
+------+------+------+
| id| fid | name |
+------+------+------+
|1 |1 | a|
|2 |1 | b|
|4 |2 | d|
|5 |2 | e|
+------+------+------+
4 rows in set (0.00 sec)