Error establishing a database connection.
This is the common issue for a WordPress site while porting from local to live or migrating from one host to other.
- Your login details for your database are wrong.
- Corrupted Database
Check Database name and user
Check Phpmyadmin whether the database imported correctly.
Check the wp-config.php, has the same database name and user, also check the password provided for user
If the above point doesn’t work, then create a new DB and import the existing database..