SQL Server 交叉表查询 case

select dbo.appraiser.quarterID,dbo.landUndertake.landcode,case dbo.landUndertake.appraiserGrade when 'appraiserID1' then dbo.landundertake.appraiserID else null END as appraiserID,case dbo.landUndertake.appraiserGrade when 'appraiserID2' then dbo.landundertake.appraiserID else null END as appraiserID1
from dbo.LandUndertake inner join
dbo.Appraiser ON dbo.LandUndertake.quarterID=dbo.appraiser.quarterID and dbo.landundertake.appraiserID=DBO.Appraiser.appraiserID
Group by dbo.appraiser.quarterID,dbo.landUndertake.landcode,dbo.landundertake.appraiserGrade,dbo.landundertake.appraiserID