DZ2.5升级3.1问题，源码备份

老师们，本人菜鸟，我原有2.5的模板现在如何才能升级到3.1呢？ 我现在直接把我备份的传到3.1里升级失败有错误

(1054) Unknown column 'allowbegincode' in 'field list'SELECT `groupid`,`readaccess`,`allowgetattach`,`allowgetimage`,`allowmediacode`,`maxsigsize`,`allowbegincode` FROM common_usergroup_field

PHP Debug

No.	File	Line	Code
1	admin.php	57	require(%s)
2	source/admincp/admincp_tools.php	36	updatecache()
3	source/function/function_cache.php	26	call_user_func(%s)
4			build_cache_usergroups()
5	source/function/cache/cache_usergroups.php	17	table_common_usergroup_field->fetch_all_fields(%s, Array)
6	source/class/table/table_common_usergroup_field.php	36	discuz_database::fetch_all(%s, Array, %s)
7	source/class/discuz/discuz_database.php	100	discuz_database::query(%s, Array, false, false)
8	source/class/discuz/discuz_database.php	136	db_driver_mysql->query(%s, false, false)
9	source/class/db/db_driver_mysql.php	153	db_driver_mysql->halt(%s, %d, %s)
10	source/class/db/db_driver_mysql.php	224	break()

提示字段不存在，重新升级一下