mysql> select * from test;;
+----+------+
| id | num |
+----+------+
| 1 | NULL |
| 2 | NULL |
| 3 | NULL |
| 4 | NULL |
| 5 | NULL |
+----+------+
5 rows in set (0.00 sec)
mysql> update test set num = rand(12)*1000000;
Query OK, 5 rows affected (0.00 sec)
Rows matched: 5 Changed: 5 Warnings: 0
mysql> select * from test;
+----+--------+
| id | num |
+----+--------+
| 1 | 157418 |
| 2 | 629671 |
| 3 | 676102 |
| 4 | 491496 |
| 5 | 429176 |
+----+--------+
5 rows in set (0.00 sec)
