Mega Code Archive
If you wanted to trim leading and trailing characters, you would use the keyword BOTH
mysql>
mysql> SELECT TRIM(BOTH 'XXX' FROM "XXXFileNameXXX");
+----------------------------------------+
| TRIM(BOTH 'XXX' FROM "XXXFileNameXXX") |
+----------------------------------------+
| FileName |
+----------------------------------------+
1 row in set (0.00 sec)
mysql>