Why do I have different usernames from mysql.user and select user()? With 10.4.6-MariaDB on my Mac OS 10.14.5
Logged in as root I can see the list of users on my server with 

MariaDB [(none)]&gt; select Host,User from mysql.user;
+--------------+-----------+
| Host         | User      |
+--------------+-----------+
| localhost    |           |
| localhost    |           |
| localhost    | root      |
| localhost    | user_Name |
| PCName.local |           |
+--------------+-----------+
5 rows in set (0.001 sec)


but when logged in as user_Name and I check the current user

MariaDB [(none)]&gt; select user()
    -&gt; ;
+-------------------------------+
| user()                        |
+-------------------------------+
| user_Name@localhost@localhost |
+-------------------------------+
1 row in set (0.000 sec)


That doesn't seem right to @localhost written twice. 

So my question is why this happening?
What you should run is this

Please run this query:

SELECT USER(),CURRENT_USER();


What do these functions return ???


USER() reports how you attempted to authenticate in mysqld
CURRENT_USER() reports how you were allowed to authenticate by mysqld


Please note that CURRENT_USER() should return something from mysql.user. You said that USER() returns user_Name@localhost@localhost. If CURRENT_USER() comes back with the same response as USER(), then MariaDB has a bug.

Since USER() reports how you attempted to authenticate in mysqld, my guess would be that's probably how you typed it.

mysql -u user_Name@localhost


You should login to MariaDB like this

mysql -u user_Name -hlocalhost


Try it again and see. I discussed this before in this forum : MySQL error: Access denied for user &#39;a&#39;@&#39;localhost&#39; (using password: YES)