Is it possible to recover Deleted users?

When you work with any type of database it is of UTMOST importance to create regular backups. Once you delete something from a database it is gone forever. This is what they teach in the first class of any database course.

Here is a link to a question in DB stackexchange

I highly doubt they can do anything about it, but do contact your webhost to see if they can do anything.

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