Unable to connect to the MySQL server

Hello, Can you explain to us how you proceeded with your installation? To perform a LAMP installation (Linux, Apache, MySQL, PHP), you just need to run:

sudo apt update
sudo apt install apache2 default-mysql-server libapache2-mod-php phpmyadmin

From then on, phpMyAdmin is accessible at http://server/phpmyadmin (replacing server with the IP address or hostname of the server). Good luck

Hello grandmother/master,
thank you for replying to my message.

I had already installed MySQL.
I went to the Ubuntu 20.10 Synaptic package manager, refreshed and upgraded everything. I noticed that phpMyAdmin was not installed. I chose to install it.
At the end of the installation, it asked me to enter a password, which I did. At the very end, a window appeared telling me that it could not find a file. Unfortunately, I lost track of that information.
Is there a way to search the installation log?

Sorry, but I am a complete beginner: How to know the IP address and the server name?
In addition, I did this with Firefox, http://serveur/phpmyadmin and Firefox says it detected a potential security threat and refuses to continue!

Hello,

What you can do is purge the package and reinstall it:

sudo apt purge phpmyadmin
sudo apt install phpmyadmin

How to know the IP address and the server name?

If you run the browser on the same system as the web server (here apache2), you can connect to phpmyadmin via the local interface (lo), whose IP is traditionally 127.0.0.1 (as shown by the command ip addr), or via the associated name (localhost) defined in /etc/hosts, which gives the options:
- http://localhost/phpmyadmin
- http://127.0.0.1/phpmyadmin

Note that you could use the IP of your network interface or the name you chose for your machine (information available in the same places). If you enter the URL correctly, you should not see a security warning. So for example if your machine is named toto and has a local IP address 192.168.1.10 you could also connect via the URLs:
- http://toto/phpmyadmin
- http://192.168.1.10/phpmyadmin

If the web server and the browser are on two different machines, you simply need to obtain the server’s IP address (which must be routable from the client machine) or designate it by its FQDN, which must be resolved on the client machine by /etc/hosts or by a DNS defined in /etc/resolv.conf.

To go further:
This second scenario is essentially what happens when you go to a website (for example www.google.fr). Your browser asks the system (here Linux) to connect to www.google.fr, but to open the connection your system needs to know the corresponding IP. To do this it consults /etc/hosts to see if the answer is there. If not, it triggers a DNS query to one of the servers defined in /etc/resolv.conf (typically your ISP’s DNS server, defined when you connect to your box) which returns the IP of www.google.fr.

Good luck

Hello mamiemando,
I tried to purge and then reinstall phpmyadmin as you advised and I got this:

sudo apt purge phpmyadmin
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
 dbconfig-common dbconfig-mysql icc-profiles-free libapache2-mod-php7.4
 libblkid-dev libffi-dev libglib2.0-dev libglib2.0-dev-bin libjs-openlayers
 libmount-dev libonig5 libselinux1-dev libsepol1-dev libsqlite0 libzip5 php
 php-bz2 php-curl php-gd php-google-recaptcha php-mbstring
 php-phpmyadmin-motranslator php-phpmyadmin-shapefile
 php-phpmyadmin-sql-parser php-phpseclib php-psr-cache php-psr-container
 php-psr-log php-symfony-cache php-symfony-cache-contracts
 php-symfony-expression-language php-symfony-service-contracts
 php-symfony-var-exporter php-tcpdf php-twig php-twig-extensions php-xml
 php-zip php7.4 php7.4-bz2 php7.4-cli php7.4-curl php7.4-gd php7.4-json
 php7.4-mbstring php7.4-opcache php7.4-readline php7.4-xml php7.4-zip
 uuid-dev
Please use “sudo apt autoremove” to remove them.
The following packages will be REMOVED:
 phpmyadmin*
0 updated, 0 newly installed, 1 to remove and 1 not upgraded.
After this operation, 27.2 MB of disk space will be freed.
Proceed with removal? [Y/n] O
(Reading database... 345494 files and directories currently installed.
)
Removing phpmyadmin (4:4.9.7+dfsg1-1) ...
Determining localhost credentials from /etc/mysql/debian.cnf: succeeded.
dbconfig-common: dumping mysql database phpmyadmin to /var/tmp/phpmyadmin.phpmya
dmin.2021-04-29-20.08.mysql.OBx2Mf.
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run
/mysqld/mysqld.sock' (2).
unable to connect to mysql server.
error encountered dumping database:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run
/mysqld/mysqld.sock' (2)
dbconfig-common: phpmyadmin remove: aborted.
dbconfig-common: flushing administrative password
dpkg: error processing package phpmyadmin (--remove):
 installed phpmyadmin package pre-removal script subprocess returned error exit 
status 1
dpkg: too many errors, stopping
Determining localhost credentials from /etc/mysql/debian.cnf: succeeded.
dbconfig-common: flushing administrative password
Errors were encountered during processing:
 phpmyadmin
The operation was halted because there were too many errors.
E: Sub-process /usr/bin/dpkg returned an error code (1)

What to do?

Whoa, I don’t know how you installed phpmyadmin (or rather mysql) but basically the uninstallation fails because it tries to back up the phpmyadmin database, or your MySQL server isn’t running, or isn’t even installed.

Start by checking that your MySQL server (= MariaDB) is installed and running. In theory you should be able to start it with the command:

systemctl status mariadb

If that fails, (re)install MySQL and verify it has started:

sudo apt update
sudo apt install default-mysql-server
systemctl status mariadb

You should then be able to purge and reinstall phpmyadmin:

sudo apt purge phpmyadmin
sudo apt install phpmyadmin

Good luck

But I don’t understand why you say MySQL is poorly installed, since I can show you that it works with the following:

sudo service mysql start
[sudo] Mot de passe de thomas : 
thomas@thomas-K53SD:~/Documents/DATABASE$ mysql -p Essai
Enter password: 
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.23-0ubuntu0.20.10.1 (Ubuntu)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

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

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

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| Essai |
| information_schema |
+--------------------+
2 rows in set (0.00 sec)

mysql> describe T_Essai;
+-----------+-----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-----------+------+-----+---------+----------------+
| id_Essai | int | NO | PRI | NULL | auto_increment |
| NOM | char(200) | YES | | NULL | |
| PRENOM | char(20) | YES | | NULL | |
| TELEPHONE | char(15) | YES | | NULL | |
| MAIL | char(20) | YES | | NULL | |
| VILLE | char(100) | YES | | NULL | |
| PAYS | char(100) | YES | | NULL | |
+-----------+-----------+------+-----+---------+----------------+
7 rows in set (0.00 sec)

mysql> 

je te rappelle que j'ai installé mysql client et serveur avec le gestionnaire synaptique de Ubuntu, l'an dernier. J'ai travaillé avec sans rencontrer de pb particulier. Puis avec le même gestionnaire, j'ai installé apache2 dont j'ai vérifié hier encore, qu'il se lance avec systemctl status sans relever d'erreur. Ce n'est qu'en installant phpmysql que ce dernier relève une erreur !
Mais pourquoi ne pas examiner les logs des installations ? pourrais-tu me dire où les trouver et saurais-tu les analyser ?
Merci d'avoir examiné ce pb et d'avoir pris le temps de me répondre !

Encore une précision: je n'ai pas mariadb. Est-ce indispensable pour phpmyadmin ?

Encore une preuve du démarrage de mysql:

systemctl status mysql
● mysql.service - MySQL Community Server
 Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset:>
 Active: active (running) since Fri 2021-04-30 11:20:17 CEST; 29min ago
 Main PID: 228536 (mysqld)
 Status: "Server is operational"
 Tasks: 38 (limit: 9169)
 Memory: 352.3M
 CGroup: /system.slice/mysql.service
 └─228536 /usr/sbin/mysqld

avril 30 11:20:15 thomas-K53SD systemd[1]: Starting MySQL Community Server...
avril 30 11:20:17 thomas-K53SD systemd[1]: Started MySQL Community Server.