mysql> DROP INDEX idx-ipt ON sf_ipt_exam_item;
1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '-ipt ON sf_ipt_exam_item' at line 1
mysql>
错误原因是语法问题，SQL语句中存在'-'符号，需要用'`'包裹，正确语法如下:
mysql> DROP INDEX `idx-ipt` ON `sf_ipt_exam_item`;
Query OK, 0 rows affected
Records: 0 Duplicates: 0 Warnings: 0
mysql>
MySQL查询索引语句:
SHOW INDEX FROM `sf_ipt_exam_item`