EN 
PL 
DE 
An error establishing a database connection in WordPress is one of the most frustrating and common situations that website administrators can encounter. Whenever WordPress is unable to connect to the database, it displays this message. Whatever the reason, there are specific steps you can take to fix the problem.
1. Check your database login details
The first thing we should do is check if our database login details are correct. This information is stored in the wp-config.php file, which is located in the WordPress root directory. This file contains four key pieces of information: the database name (DB_NAME), the database user (DB_USER), the database password (DB_PASSWORD), and the database host (DB_HOST). We need to ensure that this information is correct and consistent with that used by our hosting provider.
2. Check the database server
If our login details are correct, the next step is to verify that our database server is working properly. Sometimes, due to overload or failure, the database server may be unavailable. In this case, we should contact our hosting provider and ask them to check the server status.
3. Repair your database using WordPress features
There is a built-in feature in WordPress that allows you to repair your database. To enable it, we need to open the wp-config.php file and add the following line of code:
define('WP_ALLOW_REPAIR', true);Then, by entering the address of the website followed by /wp-admin/maint/repair.php in the browser (e.g. mojastrona.pl/wp-admin/maint/repair.php) we gain access to the database repair tool. Once the repair process is complete, it is very important to remove the line of code that we added to the wp-config.php file.
4. Use the database repair plugin
If the above methods do not work, we can use one of many database repair plugins. One of them is “WP-DBManager”, which allows you to easily manage your WordPress database from the administrative dashboard. The plugin allows you to repair, optimize, backup, restore, delete and test your database.
5. Contact your hosting provider
If none of the above methods work, the final solution is to contact your hosting provider. They can help diagnose and solve the problem.
Remember that a database connection error in WordPress can be the result of many different factors. These methods are just the most common solutions, but you may need to take further steps to resolve the issue.