I experienced the same problem. I am describing below my solution:
mysql> DROP DATABASE mydatabase;
ERROR 1010 (HY000): Error dropping database (can't rmdir '.\mydatabase', errno: 13)
I went to delete this directory: C:\Users\jaimemontoya\...\core\mysql\data\mydatabase
.
mysql> DROP DATABASE mydatabase;
ERROR 1008 (HY000): Can't drop database 'mydatabase'; database doesn't exist
mysql> CREATE DATABASE mydatabase;
Query OK, 1 row affected (0.00 sec)
That created again folder C:\Users\jaimemontoya\...\core\mysql\data\mydatabase
containing this file: db.opt
.
mysql> SHOW databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| phpmyadmin |
| sys |
+--------------------+
5 rows in set (0.00 sec)
mysql> exit
Bye
After the database was created, I imported data to the database and my C:\Users\jaimemontoya\...\core\mysql\data\mydatabase
was populated with many more files. Three files per table of my database using the following extensions:
[table].frm
[table].MYD
[table].MYI