不同适用于所有列,因此您可以使用聚合函数:
select mp.PermitNumber, mp.PermitName, max(mod.[CreatedOn])as [CreatedOn] from tblPermit mp Inner join dbo.[tblModification] mod on mod.PermitId = mp.PermitId Group by mp.PermitNumber, mp.PermitName order by 1

不同适用于所有列,因此您可以使用聚合函数:
select mp.PermitNumber, mp.PermitName, max(mod.[CreatedOn])as [CreatedOn] from tblPermit mp Inner join dbo.[tblModification] mod on mod.PermitId = mp.PermitId Group by mp.PermitNumber, mp.PermitName order by 1