Query conversion

Hi All,

Please help me to convert the following MS SQL query (part of the trigger) to Oracle query:

       SELECT inserted.serial_nbr,

              'PORT' + RIGHT(REPLICATE('0',6) + CONVERT(varchar,inserted.serial_nbr),6)

         FROM inserted

              LEFT OUTER JOIN s1_name_and_address snaa

                ON 'PORT' + RIGHT(REPLICATE('0',6) + CONVERT(varchar,inserted.serial_nbr),6) = snaa.name_and_address_id

        WHERE snaa.name_and_address_id IS NULL

Thank you,

Olivera