Delete a Database using Database Configuration Assistant(DBCA).

Go to following location :

      ORACLE_HOME/bin 

 

Execute below command :

     ./dbca.sh (If database is installed on Linux)
     ./dbca.bat (If database is installed on Windows)

Click on Next.

Select "Delete a Database" option and then click Next.

Select the database that you want to delete and also enter database username and password. Click on Finish.

Click on Yes.

Click on Yes.

 Selected database is deleted.