Rounds X to D decimal places.
Returns the result as a string.
If D is 0, the result has no decimal point or fractional part.
mysql>
mysql> SELECT FORMAT(12332.123456, 4);
+-------------------------+
| FORMAT(12332.123456, 4) |
+-------------------------+
| 12,332.1235 |
+-------------------------+
1 row in set (0.00 sec)
mysql>