IntegrityError: columns ticket, time, field are not unique

[yifan.liu@…]

7. Import bugs and bug activity...

Traceback (most recent call last):

File "G:\Documents and Settings\Administrator\Desktop\bugzilla2trac.py", line 895, in ?

main()

File "G:\Documents and Settings\Administrator\Desktop\bugzilla2trac.py", line 892, in main

convert(BZ_DB, BZ_HOST, BZ_USER, BZ_PASSWORD, TRAC_ENV, TRAC_CLEAN)

File "G:\Documents and Settings\Administrator\Desktop\bugzilla2trac.py", line 672, in convert

value = descthetext?)

File "G:\Documents and Settings\Administrator\Desktop\bugzilla2trac.py", line 365, in addTicketComment

(ticket, time.strftime('%s'), author, 'comment', , comment))

File "G:\Python24\Lib\site-packages\trac\db\util.py", line 50, in execute

return self.cursor.execute(sql_escape_percent(sql), args)

File "G:\Python24\Lib\site-packages\trac\db\sqlite_backend.py", line 56, in execute

args or [])

File "G:\Python24\Lib\site-packages\trac\db\sqlite_backend.py", line 48, in _rollback_on_error

return function(self, *args, kwargs)

IntegrityError: columns ticket, time, field are not unique

When I transfered the data from bugzilla to the trac, I got this error all the times. Who can explain the reason? :)