text: #include <db.h> int DBcursor->del(DBC *DBcursor, u_int32_t flags);
  The
  DBcursor->del() method deletes the key/data pair to which the
  cursor refers.
  When called on a cursor opened on a database that has been made into a secondary index using the DB->associate() method, the DB->del() method deletes the key/data pair from the primary database and all secondary indices.
  The cursor position is unchanged after a delete, and subsequent calls to cursor functions expecting the cursor to refer to an existing key will fail.
  The
  DBcursor->del() method will return DB_KEYEMPTY if
  the element has already been deleted. The
  DBcursor->del()
  method returns a non-zero error value on failure and 0 on success.
  The flags parameter must be set to 0 or one of the following values:
  The
  DBcursor-.
  If the cursor has not been initialized; or if an invalid flag value or parameter was specified.
  Write attempted on read-only cursor when the DB_INIT_CDB flag was specified to DB_ENV->open().
  Database Cursors and Related Methods