Error establishing a database connection when setup wordpress

@handymovik I'd be happy to help point you in the right direction! I can't be sure which instructions you followed when you set this up, but I will go through some of the instructions we have in our Guide - Install WordPress on Ubuntu 18.04.

Hostname Setup

You mention that you can't get past step number two. To be certain everything is set up from the beginning of these instructions, you'll want to check that your host name is set to match your domain.

Checking MySQL

• You will also want to make sure the database service is running. You can check this using the below command to check and see if this service is listening and accepting connections. You will want to check for any mention of mysql.

sudo netstat -plunt

and then the below command, if mysql is not mentioned in that output:

sudo systemctl start mysql

• It may also be helpful to review the information in your MySQL error logs.

sudo cat /var/log/mysql/error.log 

• From there, you can check your database permission by logging into the MySQL as the root user. Keep in mind that this user will differ from the root user of your Linode. This is where you will create a WordPress user that will have permissions to access this specific database.

Troubleshooting wp-config.php Access

You mention that you can't connect to your wp-config.php file. If I'm understanding you correctly, this may be a permissions issue. If this is not the case, please, feel free explain what you mean when you say that you can't enter the file.

• The wp-config.php file is created when WordPress is installed. If you are unable to access this file, the permissions for the website directory may need to be changed to set the web server's user as the owner.

For example:

sudo chown -R www-data:www-data /var/www/html/example.com/

• After you've gained access to your wp-config.php file, you will want to review the database connection information which is located towards the beginning of the database information.

For example:

/** The name of the database for WordPress */
define('DB_NAME', 'database_name');

/** MySQL database username */
define('DB_USER', 'database_username');

/** MySQL database password */
define('DB_PASSWORD', 'database_password');

I hope this information helpful is helpful. Feel free to check out the below official WordPress resources for more information.

Additional Resources

• Editing wp-config.php
• WordPress Forum
• Troubleshooting Web Servers, Databases, and Other Services

Did you set up a root user for MySQL? The WP setup doesn't do this for you and depends on it being done ahead of time. Unless you choose specifically, the ssh login information is not the same for MySQL (or the default).

Do you have port 3306 blocked in your firewall?

-- sw

hi @rdaniels
i set up it like your guide Install WordPress on Ubuntu 18.04 but it not working. it still has error

Hi,
I installed WordPress on cPanel, which is deployed on the Linode centos 7 server. Everything works fine when I run the website with local MySql. But When I am trying to connect with the Linode Database node (external) then the problem comes out. WordPress shows 'Error establishing a database connection'.

I just changed the username, password, dbname and in the hostname. I used the host URL I got from the database instance. with port:3306. example: …………….-primary.servers.linodedb.net:3306 and without port. With public and private both addresses.

Summary is: I just restored my db to the Linode database and trying to connect with the database with my WordPress.

Do I need to do anything else? I need to solve it urgently.

With regards.
Rajib Ahmed