quizas la función format de mysql te ayude.
Código mysql:
Ver original+---------+
| num |
+---------+
| 1.00002 |
| 2.1 |
| 3.1 |
| 1256.36 |
+---------+
+---------------+
+---------------+
| 1.00 |
| 2.10 |
| 3.10 |
| 1,256.36 |
+---------------+
mysql>
saludos