SELECT [Code] ,[AlarmID] ,[ItemName] ,[isDeleted] ,[Remark] FROM [LjlData].[dbo].[T_BaseDetail] union select 0--

SELECT  [id]       ,[AlarmID]       ,[ItemName]       ,[isDeleted]       ,[Remark]   FROM [LjlData].[dbo].[T_BaseDetail] union select 0 ,'','',''--

union 后面的列要和前面一样  而且要类型相同