I am assuming that the DBA deleted the project schema from the DB on purpose and not as an accident. IF this is the case then the project will still be listed within the Site Projects list within the Site Admin. This is expected because the correct way ti remove a project from the Site Admin list would be one of 2 ways:
1) If you just want to remove the project from the list but have the resources for that project remain intact (project's repository files remain within the project repository and the project schema to remain in the db) then you would select the project and choose the ''remove project'' option (can be found through right clicking). this would effectively remove the project from project list within the Site Projects tab, but leave the resources intact to be restored at a later time
2) If you just want to permanently delete the project from the list and delete the resource es as well (project's repository files within the project repository and the project schema in the db) will be permanently removed and unrecoverable) then you would select the project and choose the ''delete project'' option (can be found through right clicking). This would effectively remove the project from project list within the Site Projects tab, while deleting all of the project resources from the project repository and the DB. This is unrecoverable so it is recommended that you create back ups to be archived prior to performing a delete as it is unrecoverable.
These two options are the recommendations to getting the project out of the projects list within the Site Projects tab within site admin. Both resources are necessary for the project to be useable (the project repository component and the db schema for the project).
Since your DBA deleted the project schema the project is no longer useable. You can try to delete or remove the project within site admin (see above for reasons to choose each and warnings), and perform the project removal. through a right click. It may fail with and error, but many times accepting the error and then refreshing the projects list will reveal it has in effect been removed. If you are not able to get this to work and only consistently receive an error message through the process then you will need to go into the qcsiteadmin_db schema within the DB and within the PROJECTS table within it have the row that references that project removed from that table. Then you should be able to refresh the site projects list and have it reflected as removed (you may hev to in some instances cycle the services for ALM to get the table updated and reflected correctly within the Site Projects tab.
I hope this answers your questions.