mysql lower()函数

mysql> select " DFREF";
+--------+
| DFREF  |
+--------+
|  DFREF |
+--------+
1 row in set (0.00 sec)


mysql> select lower(" DFREF");
+-----------------+
| lower(" DFREF") |
+-----------------+
|  dfref          |
+-----------------+
1 row in set (0.00 sec)