修复db_owner的login name为sa

恢复数据库后用sp_helpuser查看，发现
> UserName GroupName        LoginName DefDBName UserID SID
> -------- ---------------- --------- --------- ------ ---
> dbo      db_owner         NULL      NULL      1      0x01

第一次见这种情况，幸好下面SQL语句可以修复db_owner的login name为sa
exec sp_configure 'allow updates', '1'
go
RECONFIGURE WITH OVERRIDE
go

update sysusers
set sid = (select sid from master..syslogins where loginname = 'sa'), updatedate = getdate(), status = (status & ~1) | 2
where name = 'dbo'

exec sp_configure 'allow updates', '0'
go
RECONFIGURE WITH OVERRIDE
go