Use the drop database command to remove a database. drop database deletes the database and all of its contents from Adaptive Server, frees the storage space that had been allocated for it, and deletes references to it from the master database.
See the Reference Manual: Commands.
You cannot drop a database that is in use, that is, open for reading or writing by any user.
You can drop more than one database in a single command. For example:
drop database newpubs, newdb
You can remove damaged databases with drop database. If drop database does not work, use dbcc dbrepair to repair the damaged database before you drop it.