mysql>
mysql> CREATE TABLE Employee (
-> last_name VARCHAR(30) NOT NULL,
-> KEY lastname_idx (last_name(3))
-> );
Query OK, 0 rows affected (0.03 sec)
mysql>
mysql> SHOW KEYS FROM Employee;
+----------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment |
+----------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
| Employee | 1 | lastname_idx | 1 | last_name | A | NULL | 3 | NULL | | BTREE | |
+----------+------------+--------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
1 row in set (0.00 sec)
mysql>
mysql> drop table Employee;
Query OK, 0 rows affected (0.02 sec)
mysql>