如果选择MS SQL Server 2008，则保留单元格的原始值

UPDATE  [MyDatabase].[dbo].[Device] 
SET nDeviceTypeID =(SELECT nDeviceTypeID FROM
        DeviceType WHERE sDisplayName =COALESCE (@Role,sDisplayName))
WHERE nDeviceID  IN (SELECT nDeviceID FROM [MyDatabase].[dbo].[AddressList]
WHERE sNetworkAddress LIKE '%' + @NetworkAddress2 + '%')
UPDATE  [MyDatabase].[dbo].[Device] 
SET nDevic