Log in to QC as admin and select the project for which you want to see the database.Once you click on the project u can automatically see the list of tables and once you click on the table u can see the list of fields for that table.
I have installed qc 9.0 starter edition in my home PC. so i have admin rights. i want explore qcsiteadmin_db.i have donwloaded excel add in as well. but in tools i cant find any "excel report".
In site admin only "migration" option is there
There are two different URL for login into QC. Once as a User & Another has an admin. I think if you login has an administrator you would be able to see the QC tables by performing the steps mentioned by pragnyareddy.
For Excel Addin, I think you are not using the right version of MS office which is compatible for QC 9.