We can delete Pluggable database using Database Configuration Assistant (DBCA) OR manually from SQL prompt as sysdba privilege.
Here I have covered DBCA to delete Pluggable database in silent and GUI mode.
/oracle/product/18.104.22.168/bin:>dbca -silent -deletePluggableDatabase -pdbName PDB12 -sourceDB CDB12
Deleting Pluggable Database
Look at the log file "/oracle/cfgtoollogs/dbca/CDB12/PDB12/CDB12.log" for further details.
Start “Database Configuration Assistant” by issuing “dbca” command from bin library as shown below.
On “Database Operation” prompt, select the “Manage Pluggable Databases”.Click Next to continue.
Select the “Delete a Pluggable Database” radio button & click Next.
On “Database List” prompt, select the Container Database.
On “Delete Pluggable Database” prompt, select pluggable database to be deleted from drop down list & click Next.
Review summary about your provided database and click Finish button.
PDB2 – Pluggable database has been deleted successfully.