Database error help! #1062 – Duplicate entry '123' for key 1

Hello all,

I’m trying to reinstate an old blog after it being down for a few months. I had its databases, etc backed up and emailed to me in .sql formats through a plugin I’d downloaded.

But through phpmyadmin, when I try to upload the file it gives me this error: #1062 – Duplicate entry ‘123’ for key 1

Anyone know how I can fix this?? Help would be super appreciated. I’ve had this blog for years and I can’t bear to lose all my posts. Thank you in advance.