BEGIN
  FOR l_rec IN (SELECT 1
                  FROM user_tables
                 WHERE table_name = 'EXT_POSTCODES') LOOP
    EXECUTE IMMEDIATE 'DROP TABLE ext_postcodes';
  END LOOP;
END;
/
create table ext_postcodes
(
  field_1  varchar2(240),
  field_2  varchar2(240)
   )  
   ORGANIZATION EXTERNAL
( type oracle_loader
default directory webmip_bulk_load
access parameters
( records delimited by NEWLINE
  READSIZE 10485760
  skip 1
  fields terminated by ',' 
  optionally enclosed BY '"'
  missing field values are null
  (
  field_1,
  field_2
  )
)
location ('POSTCODES.csv')
)
reject limit unlimited
/