Access denied for user ''@'localhost' (using password: NO) When Upgrading Wordpress

Question

I just tried to upgrade the latest wordpress version, and it throws this error. Access denied for user ''@'localhost' (using password: NO) . I immediately communicated it to the service provider, they say it is a database error. But i checked the wp-config file with correct database name, username and password, It is all perfect. But why still im getting the same error, Its a server problem or anything has corrupted while upgrading the wordpress version.

Answer 1

There are many reasons for having such problems:

• Hosting provider problems
• Wrong DB info in wp-config
• A hostname issue. Are you using localhost as a DB_HOST ? Some hosting companies do not work with localhost . See codex reference for more.
• Database tables need repair/optimization. Wordpress has an in built functionality to achieve this .
• Changes in the way wordpress handles databases. Similar post and solution .

In your case I would go with the last one, as you say that the issue came up after the update