Error Establishing a Database Connection in WordPress with Ubuntu 16.04.3 NGINX, MARIADB 10, PHP7/7.1 and Wordpress 4.8.2

Have your created a database and user and tested that the connection works outside the scope of WordPress?

Here is a simple bash script to test the connection (adjust as needed)

#!/usr/bin/env bash

WEBROOT=${HOME}/public_html

WPDBHOST=$(cat ${WEBROOT}/wp-config.php | grep DB_HOST | cut -d \' -f 4)
WPDBNAME=$(cat ${WEBROOT}/wp-config.php | grep DB_NAME | cut -d \' -f 4)
WPDBUSER=$(cat ${WEBROOT}/wp-config.php | grep DB_USER | cut -d \' -f 4)
WPDBPASS=$(cat ${WEBROOT}/wp-config.php | grep DB_PASSWORD | cut -d \' -f 4)
WPDBPREF=$(cat ${WEBROOT}/wp-config.php | grep "\$table_prefix" | cut -d \' -f 2);

if [ ! "`mysql -u${WPDBUSER} -p${WPDBPASS} -e 'SHOW DATABASES;' | grep ${WPDBNAME}`" == "${WPDBNAME}" ]; then
  echo "${WPDBNAME} connection failure for ${WPDBUSER}"
  exit
else
  echo "${WPDBNAME} connected"
fi

Hello all,

If you’re unable to access the database using the credentials then the password is likely to be wrong. You can try to reset the passwords for the databases that you’re unable to access.

You can also check our article on How To Debug the WordPress “Error Establishing Database Connection”:

https://www.digitalocean.com/community/tutorials/how-to-debug-the-wordpress-error-establishing-database-connection

Regards, Alex