Does an administrator access allow someone to access to the WordPress database?

No, wp-admin Administrator access does not grant direct access to files or the database. However, as an Administrator, you can install / activate / use / deactivate / uninstall plugins, and there are a number of plugins which can take backups of the files and the database. So, anything WordPress has access to, they would have access to.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)