mysql> desc test;
+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| a     | int(11) | YES  |     | NULL    |       |
| b     | int(11) | YES  |     | NULL    |       |
+-------+---------+------+-----+---------+-------+
2 rows in set (0.00 sec)

mysql> insert into test values(1,1);
....
mysql> insert into test values(7,7);
mysql> select (a*b) as g,a,b from test where a<>b and a<7 and b<7
 and floor(sqrt(a*b))=sqrt(a*b) order by g;
+------+------+------+
| g    | a    | b    |
+------+------+------+
|    4 |    1 |    4 |
|    4 |    4 |    1 |
+------+------+------+
2 rows in set (0.00 sec)