此函数比较简单，大家看看作为了解即可：
MySQL可以通过field()函数自定义排序，格式：field(value,str1,str2,str3,str4)，value与str1、str2、str3、str4比较，返回1、2、3、4，如遇到null或者不在列表中的数据则返回0. 这个函数好像Oracle中没有专门提供（也可能是我没有用到），不过自己实现这样一个函数还是比较简单的。
mysql> select * from driver_log order by name;
+--------+-------+------------+-------+
| rec_id | name | trav_date | miles |
+--------+-------+------------+-------+
| 1 | Ben | 2006-08-30 | 152 |
| 9 | Ben | 2006-09-02 | 79 |
| 5 | Ben | 2006-08-29 | 131 |
| 8 | Henry | 2006-09-01 | 197 |
| 6 | Henry | 2006-08-26 | 115 |
| 4 | Henry | 2006-08-27 | 96 |
| 3 | Henry | 2006-08-29 | 300 |
| 10 | Henry | 2006-08-30 | 203 |
| 7 | Suzi | 2006-09-02 | 502 |
| 2 | Suzi | 2006-08-29 | 391 |
+--------+-------+------------+-------+
10 rows in set (0.00 sec)
mysql> select * from driver_log order by field(name,'Suzi','Ben','Henry');
+--------+-------+------------+-------+
| rec_id | name | trav_date | miles |
+--------+-------+------------+-------+
| 2 | Suzi | 2006-08-29 | 391 |
| 7 | Suzi | 2006-09-02 | 502 |
| 1 | Ben | 2006-08-30 | 152 |
| 9 | Ben | 2006-09-02 | 79 |
| 5 | Ben | 2006-08-29 | 131 |
| 8 | Henry | 2006-09-01 | 197 |
| 6 | Henry | 2006-08-26 | 115 |
| 4 | Henry | 2006-08-27 | 96 |
| 3 | Henry | 2006-08-29 | 300 |
| 10 | Henry | 2006-08-30 | 203 |
+--------+-------+------------+-------+
10 rows in set (0.00 sec)
mysql> select * from driver_log order by field(name,'Suzi','Ben');
+--------+-------+------------+-------+
| rec_id | name | trav_date | miles |
+--------+-------+------------+-------+
| 10 | Henry | 2006-08-30 | 203 |
| 8 | Henry | 2006-09-01 | 197 |
| 6 | Henry | 2006-08-26 | 115 |
| 4 | Henry | 2006-08-27 | 96 |
| &n