I have similar problem as here. The problem is that solution proposed there does not work for me:

Just for now I have users:

| user     | host                               |
| root     |                          |
| root     | localhost                          |

both without passwords (just for now. I know it is bad!).

I'm connecting to mysql using this command:

mysql -u root -h --protocol=tcp

After I logged in, I get:

mysql -u root -h --protocol=tcp
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.1.61-log Source distribution

Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> \s
mysql  Ver 14.14 Distrib 5.1.61, for redhat-linux-gnu (x86_64) using readline 5.1

Connection id:      5
Current database:   
Current user:       root@localhost
SSL:            Not in use
Current pager:      stdout
Using outfile:      ''
Using delimiter:    ;
Server version:     5.1.61-log Source distribution
Protocol version:   10
Connection: via TCP/IP
Server characterset:    latin1
Db     characterset:    latin1
Client characterset:    latin1
Conn.  characterset:    latin1
TCP port:       3306
Uptime:         2 days 9 hours 2 min 13 sec

Threads: 1  Questions: 102  Slow queries: 0  Opens: 19  Flush tables: 1  Open tables: 12  Queries per second avg: 0.0

| USER()         | CURRENT_USER() |
| root@localhost | root@localhost |
1 row in set (0.00 sec)



How to login as 'root'@

  • @mislek - You do understand localhost is right? Its defined in hosts that way.
    – Ramhound
    May 9, 2014 at 21:08
  • 1
    Yes I know what you mean, but I don't think it is in 100% the same thing. Anyway it DOES make difference to MySQL with respect to permissions.
    – misiek
    May 12, 2014 at 6:34
  • I promise you is localhost. This is true on lamost any operating system with traditional networking support. If I were to hazard a guess if you got rid of one of the root users both @ and @localhost would still work.
    – Ramhound
    May 12, 2014 at 10:54
  • 4
    When it comes to sql is NOT localhost. This is a quirk of mysql - localhost implies listening on a socket, not binding to a port.
    – davidgo
    Feb 8, 2015 at 6:49
  • localhost resolves to ip However: MySQL uses a socker connection when on localhost, and a TCP connection when on an ip. This indeed requires different user host settings.
    – Bachi
    Jul 15, 2022 at 9:49

3 Answers 3


Good evening, it's @RolandoMySQLDBA, the author of that post you mentioned.

Look at the last three lines

Server version:     5.1.61-log Source distribution
Protocol version:   10
Connection: via TCP/IP

The last line says via TCP/IP so you are 100% using the TCP/IP protocol.


If you did, it should say

[email protected] | [email protected]

It would seem weird for the output to be

[email protected] | root@localhost

Please notice the following: Since both root users have identical grants and identical passwords (none in this case), mysqld decided to pick root@localhost. At this point, you are probably wondering, "Why would mysqld make such a choice ?"

In the DBA StackExchange, I have this 2-year-old post (MySQL error: Access denied for user 'a'@'localhost' (using password: YES)). In that past, I describe exactly how mysqld peforms user authentication. Note the paragraphs from pages 486,487 of MySQL 5.0 Certification Study Guide

There are two stages of client access control:

In the first stage, a client attempts to connect and the server either accepts or rejects the connection. For the attempt to succeed, some entry in the user table must match the host from which the clent connects, the username, and the password.

In the second stage (which occurs only if a client has already connected sucessfully), the server checks every query it receives from the client to see whether the client has sufficient privileges to execute it.

The server matches a client against entries in the grant tables based on the host from which the client connects and the user the client provides. However, it's possible for more than one record to match:

As I mentioned from the Certification Book, it's possible for more than one record to match. Therefore, mysqld made the choice.

If you delete root@localhost from mysql.user, that's one way to get SELECT USER(),CURRENT_USER(); to match. Another way is to give [email protected] a password.


Having 2 root users with identical means of being used for user authentication is the root cause as to why you cannot see [email protected]. Notwithstanding, you are using TCP/IP.


Please make sure is defined in the OS. Run this:

cat /etc/hosts | grep -c "127\.0\.0\.1"

If you get 0, then the OS does not know about it. You would need to add to /etc/hosts and restart the network and then mysql.

UPDATE 2014-04-26 20:00 EDT

What I am about to say may sound silly, but the Documentation uses TCP instead of tcp

On Unix, MySQL programs treat the host name localhost specially, in a way that is likely different from what you expect compared to other network-based programs. For connections to localhost, MySQL programs attempt to connect to the local server by using a Unix socket file. This occurs even if a --port or -P option is given to specify a port number. To ensure that the client makes a TCP/IP connection to the local server, use --host or -h to specify a host name value of, or the IP address or name of the local server. You can also specify the connection protocol explicitly, even for localhost, by using the --protocol=TCP option. For example:

shell> mysql --host=
shell> mysql --protocol=TCP

The --protocol option enables you to establish a particular type of connection even when the other options would normally default to some other protocol.

Try using protocol=TCP like this

mysql -u root -h --protocol=TCP -ANe"SELECT USER(),CURRENT_USER()"
mysql -u root -h localhost --protocol=TCP -ANe"SELECT USER(),CURRENT_USER()"

to see if it makes a difference.

UPDATE 2014-05-09 16:19

You need to look over the /etc/hosts carefully

If you see this in /etc/hosts   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

then logging in as [email protected] should work properly

If you see this in /etc/hosts       localhost

then [email protected] stands no chance of working

  • Hi, I'm happy that YOU noticed my question :). Well SELECT USER(),CURRENT_USER(); does not return any of the two results that you suggested - it says @'localhost' for both! (see updated session transcript). The hosts check returns 1. Maybe my mysql client is so smart that it translates to localhost and connects to the server like this?
    – misiek
    Apr 26, 2014 at 20:30
  • Are you saying that changing /etc/hosts in the way you prescribe is the ticket? Aug 21, 2016 at 18:38
  • 2
    So there is no solution? mysql client will think you are foo@localhost even when using mysql -u foo -h
    – CDuv
    Mar 2, 2017 at 15:18
  • 2
    Can you explain that last statement? "[email protected]" stands no chance of working?
    – Flame
    Mar 18, 2020 at 1:48

For guys who're still looking for a solution : It turns out that the server tries to get a reverse resolution of the source address if "skip-name-resolve" is not set. When connecting with user root to, this address is reverse resolved as localhost provided that your /etc/hosts contains this entry. The resolution result takes precedence over the ip address when searching the priviledges table resulting in looking for root@localhost instead of [email protected]


PHP is still trying to use the default socket location. This problem can appear if you have moved the MariaDB/MySQL folder from /var/lib/mysql to another location. In order to solve the problem you have to define the new socket's location in the /etc/php.ini file.

mysqli.default_socket =/newDBLocation/mysql/mysql.sock

Watch out, depending on which driver you use, you may have to specify the pdo_mysql.default_socket=!

In order to check your current directory run the following command in mysql:

select @@datadir;
  • This isn’t about PHP. It’s about the MySQL command line client. Not only that, it isn’t about moving the MySQL socket either. Got the wrong question perhaps?
    – Daniel B
    Feb 17, 2017 at 10:34
  • hey Daniel, when I was searching for this error I got to this post, therefore I posted my solution, so other ppl with the same problem find the solution faster than I did...
    – joelschmid
    Feb 19, 2017 at 9:04
  • That's just not how Super User works. Please follow the rules.
    – Daniel B
    Feb 19, 2017 at 9:46

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