Duplicate users in mysql.user

Question

I just did a SELECT Host, User, Password FROM mysql.user; and I get the following results :

+-------------------------------------+----------+-------------------------------------------+
| Host                                | User     | Password                                  |
+-------------------------------------+----------+-------------------------------------------+
| localhost                           | root     | *CFB0F01E12976D94C46201145940E3EF71E32742 |
| my_name_goes_here-MacBook-Pro.local | root     | *CFB0F01E12976D94C46201145940E3EF71E32742 |
| 127.0.0.1                           | root     | *CFB0F01E12976D94C46201145940E3EF71E32742 |
| ::1                                 | root     | *CFB0F01E12976D94C46201145940E3EF71E32742 |
| localhost                           |          |                                           |
| my_name_goes_here-MacBook-Pro.local |          |                                           |
| %                                   | testuser | *00E247AC5F9AF26AE0194B41E1E769DEE1429A29 |
+-------------------------------------+----------+-------------------------------------------+

How do I remove these duplicate entries? (I can also see the previous version of mysql(5.5.8) in my hard drive)

Answer 1

There are no duplicate entries. There is one row for each Host/User combination. But if you do need to remove one, have a look at DROP USER

Addition to answer

This query will show you that the empty users actually have a '' name:

SELECT Host, User, Password FROM mysql.user WHERE User LIKE '';

This means they can be removed with:

DROP USER ''@'localhost';
DROP USER ''@'my_name_goes_here-MacBook-Pro.local';

Do make sure you really want to remove them though. Maybe there are some processes that need them to be there and connect using these different hostnames.