可以用这个命令：
show index from table_name;
得到输出：
+------------------+------------+------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment | +------------------+------------+------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ | table_name | 0 | PRIMARY | 1 | id | A | 661757 | NULL | NULL | | BTREE | | | | table_name | 0 | product_id | 1 | product_id | A | 661757 | NULL | NULL | | BTREE | | | +------------------+------------+------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+ 2 rows in set (0.00 sec)
原文：http://www.cnblogs.com/charlesblc/p/7125612.html